CN102455628B - Image forming apparatus - Google Patents

Abstract

The present invention provides an image forming apparatus including: an image data acquisition unit that acquires image data representing a color image; and a frequency distribution acquisition unit that, based on the image data acquired by the image data acquisition unit, obtains assigning colors to each group to obtain a frequency distribution representing the number of occurrences of each color; and a color setting section that sets the first color that appears most often as the first color based on the frequency distribution obtained by the frequency distribution obtaining section. For the background color of the color image, the second color that appears second only to the first color is set as the color of the text in the color image, and the color that appears less than the second color is set as the color of the text in the color image. The pattern color in the color image, the pattern color is the color of a specific pattern in the color image. As a result, when an image including a pattern whose color belongs to a color system is printed, the color reproducibility of the pattern can be improved.

Description

image forming device

technical field

The present invention relates to an image forming apparatus that forms a color image.

Background technique

In some image forming apparatuses such as printers, copiers, and digital composite machines, conventionally, a color printing mode and a black and white mode are provided. The color printing modes include full-color mode and two-color mode.

In the full-color mode, printing is performed using toners of all colors equipped in the image forming apparatus, and in the two-color mode, printing is performed using black toner and a "color belonging to a color system" (specific color) other than black to print. "A color belonging to a chromatic system" is a color obtained by mixing a plurality of color toners.

The image forming apparatus implements the two-color mode as follows.

The image forming apparatus includes, for example, a plurality of color component counting units corresponding to blue components, green components, and red components on a one-to-one basis. Each color component counting unit counts pixels of its corresponding color among a plurality of pixels included in the image data.

In addition, the image forming apparatus sets the color corresponding to the color component count unit having the largest count value as a specific color (specific one color). Next, the image forming apparatus prints the black part in the image data in black, and prints the color part in the set specific color.

Generally speaking, even though many business documents are mostly composed of black characters, the corporate logo (logo) still needs to be printed in a color that belongs to the color system. This is because the color of a logo is one of the important factors that represent a business. In addition, in a document composed of black characters, it is not uncommon to print only the underlined and colored parts in colors belonging to the color system.

Furthermore, since the color of the logo is often the "corporate image color" representing the company itself, users request that the color of the logo be faithfully reproduced on paper. In addition, the underlined and colored parts are also faithfully reproduced on paper.

However, when the aforementioned image forming apparatus prints the above-mentioned document in which only colors such as logos, underlines, and colored parts belong to the color system in a two-color mode, the following problems occur.

That is, since the image forming apparatus prints the color portion using the color corresponding to the color component counting unit with the largest count value, the colors that can be used for printing the color portion are limited to those previously allocated to each color component counting unit. any of the colors.

Therefore, even if the color image to be printed uses only one color other than black, the color of the color part actually printed in the two-color mode will deviate from the true color of the color part in the color image.

Contents of the invention

An object of the present invention is to provide an image forming apparatus capable of improving the color reproducibility of a pattern when printing an image including a pattern whose color belongs to a chromatic system.

The present invention provides an image forming apparatus, characterized by comprising: an image data acquisition unit that acquires image data representing a color image; and a frequency distribution acquisition unit that, based on the image data acquired by the image data acquisition unit, obtains The color of each pixel is assigned to each group to obtain a frequency distribution representing the number of occurrences of each color; and the color setting section sets the first color with the largest number of appearances based on the frequency distribution obtained by the frequency distribution acquisition section. is the background color of the color image, and the second color that appears second only to the first color is set as the color of the text in the color image, wherein when the judgment condition including the specified condition is satisfied, the The color setting unit sets a third color that appears second only to the second color as the pattern color that is the color of the specific pattern in the color image, and the predetermined condition is that the first color is included. The difference between the sum of the number of occurrences of the predetermined target color of the color, the second color and the third color and the total number of pixels of the color image is smaller than a predetermined pattern judgment value.

Furthermore, the present invention provides an image forming apparatus characterized by comprising: an image data acquisition unit that acquires image data representing a color image; and a frequency distribution acquisition unit that converts the image The color of each pixel of the data is assigned to each group to obtain a frequency distribution representing the number of occurrences of each color; and the color setting section assigns the first color that appears most frequently based on the frequency distribution obtained by the frequency distribution obtaining section. set as the background color of the color image, and set a second color second only to the first color as the color of the text in the color image, wherein the color setting part sets the A plurality of colors appearing less than the second color in the frequency distribution is set as a pattern color that is a color of a specific pattern in the color image, and, based on any of the colors appearing less than the second color The number of appearances of a color, the number of appearances of the first color, and the number of appearances of the second color determine whether to set the full-color pattern mode. The full-color pattern mode is to use the pattern color to print the specified color. pattern mode, the image forming apparatus further includes a control unit, when the color setting unit sets the full-color pattern mode, the control unit uses the toner of the second color to print the color text in the image, and print the specific design using toner of the color of the design.

The specific patterns are, for example, non-character images such as logos, underlines, and colored parts. Usually, a document manuscript is formed by writing characters on a white sheet. In addition, patterns such as colored marks and underlines are often described in such document manuscripts. In this way, for an image mostly composed of characters and partly colored, that is, an image whose number of pixels of the design is smaller than a predetermined size determination value, the white color of the sheet becomes the background of the image. Therefore, the image data of such a document original contains colors in which white appears most frequently. In addition, the number of appearances of the color of the characters is second only to that of white.

Therefore, with the above structure, the first color with the largest number of appearances is set as the background color of the color image, the second color with the number of appearances next to the first color is set as the color of the text in the color image, and The color whose appearance frequency is less than the second color is set as the color of the specific pattern in the color image, that is, the pattern color, so when printing an image including the color pattern, the color reproducibility of the pattern can be improved.

Description of drawings

FIG. 1 is a schematic cross-sectional view of an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram showing an example of an electrical configuration of the image forming apparatus shown in FIG. 1 .

FIG. 3 is a conceptual explanatory diagram showing an example of an image of a document manuscript represented by image data.

FIG. 4A is an example of a frequency distribution diagram showing the number of occurrences of the color of each pixel in image data.

FIG. 4B is an example of a frequency histogram showing the number of occurrences of the color of each pixel in the image data.

FIG. 4C is an example of a frequency histogram showing the number of occurrences of the color of each pixel in the image data.

FIG. 5 is a flowchart showing an example of the operation of the image forming apparatus shown in FIG. 2 .

FIG. 6 is a flowchart showing an example of the operation of the image forming apparatus shown in FIG. 2 .

FIG. 7 is a flowchart showing an example of the operation of the image forming apparatus shown in FIG. 2 .

FIG. 8 is a flowchart showing an example of the operation of the image forming apparatus shown in FIG. 2 .

Fig. 9 is a flowchart showing another example of the operation of the color setting unit shown in Fig. 6 .

10 is a conceptual explanatory diagram showing an example of a frequency distribution, in which the frequency of occurrence of each color group sharing the top 4 bits of cyan, the top 4 bits of magenta, and the top 4 bits of yellow is shown.

11 is a conceptual diagram showing an example of a frequency distribution, in which a cuboid region formed by connecting the cluster aggregate to which the first color group belongs and the cluster aggregate to which the second color cluster belongs is shown by a straight line.

Fig. 12 is a perspective view schematically showing a structural example of a cluster aggregate.

Fig. 13 is an exploded perspective view schematically illustrating a structural example of a cluster assembly.

14 is a conceptual explanatory diagram for explaining processing performed by a frequency distribution acquisition unit and a color setting unit when a monochrome pattern mode is set.

FIG. 15 is a block diagram showing another example of the electrical configuration of the image forming apparatus shown in FIG. 1 .

FIG. 16 is a flowchart showing an example of the operation of the image forming apparatus shown in FIG. 15 .

FIG. 17 is a flowchart showing an example of the operation of the image forming apparatus shown in FIG. 15 .

FIG. 18 is a flowchart showing an example of the operation of the image forming apparatus shown in FIG. 15 .

Detailed ways

Embodiments of the present invention will be described below with reference to the drawings. The configurations attached with the same symbols in the respective drawings indicate the same configurations, and therefore description thereof will be omitted. In addition, in the following embodiments, a color image forming apparatus that performs full-color printing using each toner of cyan (C), magenta (M), yellow (Y), and black (K) is used as an example of the image forming apparatus. example.

However, the image forming apparatus can also perform full-color printing using each toner of red, green, blue, and black.

(first embodiment)

FIG. 1 is a schematic cross-sectional view of an image forming apparatus according to an embodiment of the present invention. The image forming apparatus 1 includes an image reading unit 200 and an image forming main unit 22 . The image reading unit 200 has a document supply unit 210, a scanner unit 220, a CIS (contact image sensor, contact image sensor) 231, a user interface unit 1 protruding from the front of the image forming main unit 22, and a reversing mechanism described later. .

The document supply unit 210 has an ADF (Automatic Document Feeder, automatic document feeder), and includes a document tray 211 , a take-up roller 212 , a platen 213 , a paper discharge roller 214 , and a paper discharge tray 215 . The document tray 211 is used to place documents to be read. The originals placed on the original tray 211 are picked up one by one by the pick-up roller 212 , and are sequentially conveyed to the platen 213 with gaps therebetween. After the document passes through the platen 213 , it is sequentially discharged to the paper discharge tray 215 by the paper discharge roller 214 .

A timing sensor (omitted in the figure) for detecting paper is provided at a predetermined position upstream of the reading position P in the document conveyance direction among the positions facing the platen 213, and the reading direction is adjusted according to the output request of the timing sensor. Take the timing of feeding the original at position P. The timing sensor is constituted by, for example, a photo interrupter.

The scanner unit 220 optically reads an image of a document to generate image data. Scanning section 220 has glass 221, light source 222, first reflector 223, second reflector 224, third reflector 225, first support 226, second support 227, imaging mirror 228 and CCD (Charged Coupled Device, charge coupled element) 229.

The scanning unit 220 uses a white fluorescent lamp such as a cold cathode fluorescent lamp as a light source 222, and consists of a first reflector 223, a second reflector 224, a third reflector 225, a first support 226, a second support 227, and an imaging system. Mirror 228 guides light from the document to CCD 229 . Since the scanning unit 220 uses a white fluorescent lamp such as a cold cathode fluorescent tube as the light source 222, its color reproducibility is superior to that of the CIS 231 described later that uses a three-color LED or the like as a light source.

When the document is not read by the document supply unit 210 , the user places the document on the glass 221 by hand. The light source 222 and the first reflector 223 are supported on the first support 226 , and the second reflector 224 and the third reflector 225 are supported on the second support 227 .

The document reading method of the image reading unit 200 adopts the following two reading modes, that is, the platform reading mode, in which the document placed on the glass 221 is read by the scanning unit 220; The 210 (ADF) acquires an original and reads the original while it is being conveyed.

In the platform reading mode, the light source 222 irradiates the original placed on the glass 221, and a line of reflected light in the main scanning direction is reflected in the order of the first mirror 223, the second mirror 224, and the third mirror 225. into the imaging mirror 228. The light incident on the imaging mirror 228 is imaged on the light-receiving surface of the CCD 229 .

CCD229 is a one-dimensional image sensor that processes originals in one line in the main scanning direction. The first support 226 and the second support 227 can move along the direction perpendicular to the main scanning direction (sub-scanning direction, arrow Y direction). The sub-scanning direction moves, and the next line is read.

In the ADF reading mode, the document supply unit 210 extracts the documents placed on the document tray 211 one by one by the extraction roller 212 . At this time, the first bracket 226 and the second bracket 227 are set at a predetermined reading position P below the reading window 230 .

When the document supply unit 210 transports the document, and the document passes above the reading window 230 provided on the transport path between the platen 213 and the output tray 215, the light source 222 illuminates the document, and a line of reflected light in the main scanning direction presses the first reflector 223. , the second reflector 224 , and the third reflector 225 are reflected in sequence and are incident into the imaging mirror 228 . The light incident on the imaging mirror 228 is imaged on the light-receiving surface of the CCD 229 . The document is then conveyed by the document supply unit 210 for reading the next line.

In addition, the document supply unit 210 also has a reversing mechanism including a switching guide member 216 , a reversing roller 217 , and a reversing transport path 218 . After the front side of the document is read in the ADF reading mode, the document is turned over by the reversing mechanism and sent to the reading window 230 again, so that the CCD 229 can read the back side of the document.

The reversing mechanism works only for double-sided reading and does not work for single-sided reading. During one-sided scanning and after scanning the back side in double-sided scanning, the switching guide member 216 is switched upward, and the paper discharge roller 214 discharges the document passing the platen 213 to the paper discharge tray 215 .

After reading the front side in the case of double-sided scanning, the switching guide member 216 is switched downward, and the reverse roller 217 conveys the document passing the platen 213 to the reverse conveyance path 218 . Then, the switching guide member 216 is switched upward, and the reversing roller 217 is reversely rotated, so that the document is re-conveyed to the platen 213 . Hereinafter, the mode in which both sides of the document are read by the reversing mechanism is referred to as a double-sided reversed reading mode.

In addition, in the ADF reading mode, the image reading unit 200 may scan the back side of the document using the CIS 231 approximately at the same time as the CCD 229 (scanner unit 220 ) scans the front side of the document while the document is being conveyed. At this time, the front side of the document on the document tray 211 conveyed by the document supply unit 210 is read by the CCD 229 when it passes above the reading window 230 , and its back side is read when it passes through the arrangement position of the CIS 231 . Among them, CIS231 uses RGB three-color LED and the like as a light source.

In this way, with the CCD 229 and the CIS 231 , the front and back sides of the document can be read when the document supply unit 210 performs a one-pass document feeding operation (one-pass) from the document tray 211 to the output tray 215 . Hereinafter, the mode of reading both sides of the document using the CCD 229 and the CIS 231 is referred to as a double-sided simultaneous reading mode.

The double-sided reverse reading mode and the double-sided simultaneous reading mode are reading modes for reading both sides of a document in the ADF reading mode. The double-sided reverse reading mode is used when you want to balance the printed image quality on both sides, and the double-sided simultaneous reading mode is used when you want to shorten the reading time if the printed image quality on both sides is unbalanced. The initial setting of the image forming apparatus 1 is the double-sided simultaneous reading mode, and when an image forming instruction is input without any mode setting operation for the reading mode, the document is processed in the double-sided simultaneous reading mode. Image reading works.

The image forming apparatus 1 includes an image forming body 22 and a stack tray 6 provided on the left of the image forming body 22 . The main image forming unit 22 has a plurality of paper feeding cassettes 461 , a paper feeding roller 462 that draws paper from the paper feeding cassettes 461 one by one and transports them to the image forming unit 40 , and a paper feed roller 462 that feeds paper from the paper feeding cassettes 461 . An image forming section 40 that forms an image. In addition, the main image forming unit 22 includes a paper feed tray 471 and a take-out roller 472 that draws out the originals placed on the paper feed tray 471 one by one toward the image forming unit 40 .

The image forming section 40 includes: a static elimination device 421 for removing residual charge from the surface of the photosensitive drum 43; a charging device 422 for charging the surface of the photosensitive drum 43 after the static electricity removal; The laser light is output to expose the surface of the photosensitive drum 43 to form an electrostatic latent image on the surface of the photosensitive drum 43; the developing devices 44K, 44Y, 44M, and 44C form cyan (C), Magenta (M), yellow (Y) and black (K) toner images of respective colors; a transfer drum 49 to which the toner images of respective colors formed on the photosensitive drum 43 are transferred 49; the transfer device 41, which transfers the toner image on the transfer drum 49 onto the paper; and the fixing device 45, which heats the paper on which the toner image is transferred, so that the toner image is fixed on the paper. on paper.

In addition, the toner cartridges omitted in the figure provide respective toners of cyan, magenta, yellow, and black. Furthermore, the main image forming unit 22 further includes transport rollers 463 and 464 for transporting the paper passing through the image forming unit 40 to the stack tray 6 or the output tray 48 .

When forming images on both sides of a sheet, the image is formed on one side of the sheet by the image forming unit 40 , and then the sheet is nipped by the transport rollers 463 on the output tray 48 side. In this state, the transport roller 463 is reversely rotated to turn the paper back, and is transported to the upstream portion of the image forming section 40 along the paper transport path PL, and an image is formed on the other side of the paper by the image forming section 40. After that, the paper is discharged to the stack tray 6 or the output tray 48.

FIG. 2 is a block diagram showing an example of the electrical configuration of the image forming apparatus 1 shown in FIG. 1 . The image forming apparatus 1 includes an ASIC (Application Specific Integrated Circuit) 10 for image processing, a user interface unit 1, a system control unit 14, an image reading control unit 15, and an image forming control unit 16 (an example of a control unit). , the management unit 17 , the operation control unit 19 , the setting unit 20 , the image forming unit 40 and the image reading unit 200 .

The image processing ASIC 10 , the system control unit 14 , the image reading control unit 15 , the image formation control unit 16 , and the management unit 17 are connected by a bus B1 so that data can be exchanged with each other. The operation control unit 19 is connected to the user interface unit 1, the image reading control unit 15 is connected to the image reading unit 200, the image formation control unit 16 is connected to the image forming unit 40, and the management unit 17 is connected to the setting unit 20. .

The image processing ASIC 10 has an image data acquisition unit 11 , a frequency distribution acquisition unit 12 , and a color setting unit 13 . The image data acquisition unit 11 acquires image data representing a color image. The image data acquisition unit 11 expresses the color of each pixel constituting the image data using density values of three predetermined elemental colors (for example, cyan (C), magenta (M), and yellow (Y)). Furthermore, the image data acquisition unit 11 expresses each density value with a predetermined basic number of digits (for example, 8 digits).

In addition, the image data acquiring unit 11 may express the image data using density values of red, green, and blue. Also in this case, each density value of red, green, and blue is represented by a basic number of bits (for example, 8 bits).

For example, the image data acquisition unit 11 may receive the color image data read from the document by the image reading unit 200 through the image reading control unit 15 to acquire the image data. For example, the image data acquiring unit 11 may acquire image data by receiving color image data from a personal computer or the like connected to the network via a network not shown in the figure. For example, the image data acquiring unit 11 may acquire image data by receiving color image data transmitted from a facsimile machine through a telephone line not shown in the figure. Alternatively, the image data acquiring unit 11 may receive image data obtained by further performing intermediate image processing (for example, processing for removing transparent back color, etc.) on these image data.

The image processing ASIC 10 performs predetermined image processing on the image data acquired by the image data acquisition unit 11 . For example, the image processing ASIC 10 (an example of an image processing unit) performs background color change processing for changing the background color in image data to a predetermined color (see, for example, US Pat. No. 6,567,544 ).

This background color change process is a process in which pixels that should show a background color (such as white) in a color image are changed to pixels of another color (for example, when the original of a color image has a dark background color, or When the color of the back side of the document shines through the front side of the document), the color of the changed pixel is changed to the color to be displayed (for example, white).

According to the image data D acquired by the image data acquisition unit 11, the frequency distribution acquisition unit 12 assigns the color of each pixel of the image data D to each statistical class (class), thereby acquiring the appearance of each color in the image data D. The number of times is the frequency distribution of the frequency. Next, the frequency distribution acquisition unit 12 outputs frequency distribution information indicating the frequency distribution to the color setting unit 13 and the image formation control unit 16 .

Wherein, the frequency distribution refers to a distribution in which when a sample has a certain variable, the range of the variable is divided into a plurality of groups, and the number of samples having the variable belonging to each group is counted as the frequency (number of occurrences) . The frequency distribution acquiring unit 12 uses a pixel as a sample and a pixel value (density value) representing the color of the pixel as a variable, and divides the color (that is, the pixel value) into a plurality of ranges to set a group. Here, the groups do not have to have a prescribed range, and pixel values (ie, colors) can also be in one-to-one correspondence with the groups.

For example, when the image data D is composed of red, blue, and yellow, red, blue, and yellow are regarded as each group, and the numbers of red pixels, blue pixels, and yellow pixels included in the image data D are regarded as each color (group) The number of occurrences (frequency) of .

A frequency distribution displayed on a two-dimensional coordinate system with the color (group) as the horizontal axis and the number of occurrences (frequency) as the vertical axis is a so-called frequency distribution graph.

The color setting unit 13 sets the color of the pattern based on the number of appearances of each color indicated by the frequency distribution obtained by the frequency distribution obtaining unit 12 . The detailed processing content of the color setting unit 13 will be described later.

The user interface unit 1 includes an operation input unit 18 (an example of an identification information input unit) with a plurality of operation keys, and a display unit 5 composed of LEDs, a touch panel, and the like.

The operation input unit 18 is constituted by, for example, a start key, various setting keys, a touch panel, and the like. For example, the operation input unit 18 and the display unit 5 may be constituted by a touch panel with a display function in which a liquid crystal display and a touch panel are integrated.

The operation control unit 19 receives a signal indicating the operation input accepted by the operation input unit 18 , and outputs a signal indicating the operation input to the image formation control unit 16 or the setting unit 20 .

Specifically, for example, when a start key of the operation input unit 18 is pressed, the operation control unit 19 outputs a signal for requesting start of image formation to the image formation control unit 16 . Also, when the operation input unit 18 accepts an operation instruction to allow execution of the monochrome pattern mode, the operation control unit 19 outputs a signal to the setting unit 20 requesting setting to allow execution of the monochrome pattern mode. Furthermore, when the operation input unit 18 accepts identification information input by the user, the operation control unit 19 outputs the identification information to the image formation control unit 16 .

In addition, the operation control unit 19 causes the display unit 5 to perform a display corresponding to a display request output from the display system control unit 14 , the image formation control unit 16 , and the like.

The system control unit 14 is constituted by, for example, a microcomputer. The system control unit 14 comprehensively controls the operation of the image forming apparatus 1 by executing a predetermined control program. The image reading control unit 15 is constituted by, for example, a microcomputer. The image reading control unit 15 controls the image reading operation of the image reading unit 200 by executing a predetermined control program.

The management unit 17 is, for example, a storage device configured using a storage unit such as a RAM (Random Access Memory). User identification information, such as an ID number, is stored in advance in the management unit 17 . In the management unit 17 , identification information of users who are allowed to form images only in the monochrome mode and identification information of users who are allowed to form images in the monochrome mode and the full-color mode are stored in a distinguishable manner.

Hereinafter, a user who is allowed to form an image only in the monochrome mode is called a monochrome-limited user, and a user who is allowed to form an image in both the monochrome mode and the full-color mode is called an unrestricted user.

In addition, the management unit 17 does not necessarily store identification information of users who are permitted to form images in the monochrome mode and the full-color mode. The black and white mode and the full color mode will be described later.

In addition, the management unit 17 stores the identification information of each user in association with charging information indicating the amount of money charged to the user.

Therefore, for example, a company that manages the image forming apparatus 1 can read out the billing information stored in the management unit 17 and request the user to pay the image forming fee. That is, in the image forming apparatus 1 , the process of storing the billing information in the management unit 17 corresponds to the billing process.

The setting unit 20 is constituted by, for example, a microcomputer. The setting unit 20 executes a predetermined control program to set whether to allow a monochromatic pattern mode described later.

Hereinafter, the setting for allowing execution of the monochrome pattern mode is referred to as pattern mode permission setting. That is, "with pattern mode permission setting" means that the user is allowed to execute the monochrome pattern mode, and "without pattern mode permission setting" means that the user is not allowed to execute the monochrome pattern mode.

The setting part 20, when the operation control part 19 outputs a signal for requesting setting to allow execution of the monochrome pattern mode, associates the information indicating the permission setting of the pattern mode with the identification information of the user who is allowed to execute the monochrome pattern mode Get up and store in the management unit 17. As a result, the setting unit 20 makes the pattern mode permission setting.

In addition, the setting unit 20 may also adopt other methods, that is, no matter who the user is, the pattern mode permission setting is made as the setting for the image forming apparatus 1 as a whole; or, for each user stored in the management unit 17 The user (identification information) stores whether there is a pattern mode permission setting, respectively.

In addition, the setting unit 20 may not be provided, and execution of the pattern mode may be uniformly permitted to users limited to the monochrome mode. In addition, the setting unit 20 does not necessarily need to set the pattern mode permission for the user who is allowed to execute the monochrome mode and the full color mode.

The image formation control unit 16 is constituted by, for example, a microcomputer. The image forming control unit 16 controls the image forming operation of the image forming unit 40 by executing a predetermined control program. The image formation control unit 16 receives image data for printing from the image processing ASIC 10 . The image forming modes of the image forming control unit 16 include a monochrome mode, a monochrome mode, a full color mode, and a monochrome pattern mode.

The black and white mode (black and white copy) is a mode for printing a black and white image based on image data on paper using only black (K) toner.

The monochrome mode is a mode in which an image based on image data is printed on paper using only one color (such as red).

The full-color mode (full-color copy) is a mode for forming an image based on image data using a plurality of colors (ie, all colors that can be formed by the image forming unit 40 ). Specifically, the full-color mode is a mode in which a color image based on image data is printed on paper using toners of cyan (C), magenta (M), yellow (Y), and black (K). Hereinafter, all colors that can be formed by the image forming unit 40 are referred to as full colors.

In addition, the full-color mode may be a mode in which printing is performed using each toner of red, green, and blue.

The monochrome pattern mode is a mode for printing an image based on printing image data on paper using two colors of pattern color and black.

The monochrome pattern mode is a mode that takes into account the following cases, that is, when a document composed of black characters partially includes a small mark formed with a color belonging to a color system, or when a document composed of black characters contains a small mark formed with a color When it belongs to the underline or colored part formed by the color of the chromatic system, the characters are formed with black toner, and the color pattern parts such as logo, underline and colored part are formed with the pattern color set by the color setting part 13 . Hereinafter, patterns such as logos, underlines, colored parts, etc. occupying a small area in one page of images are referred to as specific patterns (or specific patterns), and the colors of the specific patterns are referred to as pattern colors.

In addition, the single-color pattern mode may also be a mode in which characters are printed in a second color described later and a specific pattern is printed in a pattern color.

Furthermore, the image formation control unit 16 causes the display unit 5 to display a display screen for requesting the user to input identification information. Then, the image formation control unit 16 compares the identification information accepted by the operation input unit 18 with the identification information stored in the management unit 17 to perform user authentication.

In addition, the image formation control unit 16 uses the fee incurred by the authenticated user to perform a print job using the image forming apparatus 1 as charging information, and stores the charging information in association with the identification information of the authenticated user in the management unit 17. middle. The image formation control unit 16 charges the user by causing the management unit 17 to store the charging information.

When the image formation control unit 16 performs image formation in the full-color mode, the cost is higher than when the image formation is performed in the black-and-white mode. The cost of image formation by the image formation control unit 16 in the monochrome pattern mode and the later-described full-color pattern mode is lower than the cost of image formation in the full-color mode, for example, the same as in the black and white mode. time fee.

The image formation control unit 16 determines the image formation mode based on whether the authenticated user is an unlimited user or a monochrome-only user, whether pattern mode permission is set, and frequency distribution information. Then, the image forming control unit 16 controls the image forming unit 40 so that the image forming unit 40 forms an image on paper according to the determined image forming mode. Hereinafter, “the image formation control unit 16 causes the image formation unit 40 to form an image” is described as “the image formation control unit 16 forms an image”.

Specifically, the image formation control unit 16 allows unlimited users whose identification information is registered in the management unit 17 to perform image formation in the black-and-white mode and the full-color mode. In addition, the image formation control unit 16 prohibits image formation in the full-color mode and allows image formation in the monochrome mode for a user limited to the monochrome mode whose identification information is registered in the management unit 17 . In addition, the image formation control section 16 allows the user who has "pattern mode permission setting" whose identification information is registered in the management section 17, regardless of whether the user is a user limited to a monochrome mode or a user who is not limited, to allow a monochrome pattern. image formation in this mode. In addition, the image formation control section 16 does not necessarily need to allow image formation in the monochrome pattern mode for unlimited users.

FIG. 3 is a conceptual explanatory diagram showing an example of an image of a document manuscript represented by image data D. As shown in FIG. The image data D represents, for example, an image of a document original, that is, black text (C) occupies most of the document original, and a mark L is printed in color on the upper right part of the paper, and the color (i.e., background color) of the background (B) is White. The image data D has been subjected to background color changing processing, for example.

The symbol L is an example of a pattern, for example, it is a dark green symbol. Here, the logo L is an example of a pattern, but the pattern may be a single-color line (for example, a red underline) or a painted part painted with a single color (or a fluorescent color).

On the background (B), there is a possibility that a color different from the original background color may be mixed due to the back color passing through. However, this mixed color is changed to the background color by the background color changing process. Therefore, the colors that exist on the image data D basically include only the background color, the color of the characters, and the colors of patterns such as the logo L.

4A , 4B, and 4C are examples of frequency histograms, each showing the number of occurrences of the color of each pixel in the image data D. FIG. 4A and 4C are frequency distribution diagrams of the image data D when the logo L includes a plurality of colors. FIG. 4B is a frequency distribution diagram of the image data D when the logo L is composed of one color (monochrome).

In the frequency distribution diagrams shown in FIG. 4A , FIG. 4B , and FIG. 4C , the total number of pixels of the image data D is 551 kilopixels (k pixel). In these frequency distribution graphs, the horizontal axis represents color (equivalent to "class"), and the background color, text color, symbol color 1, symbol color 2, symbol color 3, symbol color 4, and "others" are assigned to each group. color". The vertical axis represents the number of pixels with each group of colors in the image data D, that is, the number of occurrences (frequency).

Below the horizontal axis are the number of occurrences of pixels of each color and the number of occurrences assigned in descending order of the number of appearances. Also, the number of appearances of "other colors" is the sum of the number of appearances of colors whose order of appearances is 5th or lower. In addition, the unit of the number of occurrences in FIG. 4A , FIG. 4B , and FIG. 4C is “k Pixel”.

For example, in FIG. 4A , the number of occurrences of the color of the text is 150k Pixel, which means that there are 150×1024 pixels of the color of the text in the image data D. In addition, in FIG. 4A , the number of occurrences of the logo color 3 is 0.5k Pixel, which means that there are 0.5×1024 pixels with the logo color 3 in the image data D.

Hereinafter, the color with the sequence number 1 is referred to as the first color, and the color with the sequence number 2 is referred to as the second color, that is, the sequence numbers are marked in descending order to represent the colors. That is to say, the color with the highest number of appearances in the image data D is set as the first color, and the color with the second number of appearances in the image data D is set as the second color. Similarly, the order of the number of appearances of each color is called Third to sixth colors.

In Figure 4A, the first color as the background color has the most occurrences, which is 340k Pixel. The number of appearances of the second color as the color of the text is second only to the background color, which is 150k Pixel.

The logo L shown in FIG. 4A is composed of a plurality of colors belonging to the chromatic system, for example, two colors belonging to the chromatic system, logo color 1 and logo color 2 . Where logo color 1 is the third color, logo color 2 is the fourth color. Also, for example, the colors of the pixels at the edge portion of the logo L are mixed with the colors of adjacent surrounding pixels, and logo color 3 and logo color 4 appear. Logo color 3 is the fifth color, logo color 4 is the sixth color.

Also, the third color (sign color 1) has 40k Pixels, the fourth color (mark color 2) has 20k Pixels, the fifth color (mark color 3) and the sixth color (mark color 4) The number of occurrences is 0.5k Pixel.

In addition, in Figure 4B, the first color as the background color has the most occurrences, which is 340k Pixel. The number of appearances of the second color as the color of the text is second only to the background color, which is 150k Pixel.

In FIG. 4B, the logo L is composed of logo color 1 only, that is, of a single color. Where logo color 1 is the third color. Also, for example, the colors of the pixels at the edge of the logo L are mixed with the colors of adjacent surrounding pixels, and logo color 2 and logo color 3 appear. The logo color 2 is the fourth color, and the logo color 3 is the fifth color.

In Figure 4B, the occurrence times of the third color (sign color 1) is 60k Pixel, the occurrence times of the fourth color (sign color 2) and the fifth color (sign color 3) are both 0.5k Pixel, and the sixth color ( Flag color 4) has 0 occurrences.

In Figure 4C, the first color as the background color has the most occurrences, which is 340k Pixel. The number of appearances of the second color as the color of the text is second only to the background color, which is 150k Pixel.

In FIG. 4C, the logo L is a panchromatic, ie, a multicolored logo comprising a plurality of colors belonging to a chromatic family. In addition to the logo colors 1 to 4, the logo L also includes other colors. Wherein, logo color 1 is the third color, logo color 2 is the fourth color, logo color 3 is the fifth color, and logo color 4 is the sixth color.

In Figure 4C, the third color (logo color 1) has 20k Pixels, the fourth color (logo color 2) has 0.5k Pixels, and the fifth color (logo color 3) has 0.4k pixels The number of occurrences of Pixel and the sixth color (logo color 4) is 0.3k Pixel. In addition, there are pixels of multiple colors that appear less than the sixth color, and the sum of the appearance times of pixels below the fifth color (pixels whose order number is 5 or greater) is 40.5k Pixel.

Next, the operation of the image forming apparatus 1 will be described with reference to FIGS. 5 to 8 . 5 to 8 are flowcharts showing an example of basic processing of the image forming apparatus 1 shown in FIG. 2 .

In the following description, image data D shown in FIG. 3 is used as image data to be processed. In the image data D shown in FIG. 3 , the color of the background (B) is set to the first color, and the color of the character (C) is set to the second color, and the logo L includes a number of occurrences less than that of the second color. Third to sixth colors.

First, when the user inputs identification information using the operation input unit 18 , the image formation control unit 16 compares the identification information accepted by the operation input unit 18 with the identification information stored in the management unit 17 . Then, when the identification information matches, the image formation control unit 16 authenticates the user and allows login (YES in step S1 ).

Next, for example, the image data of the document is read by the image reading unit 200 , and the image data D is acquired by the image data acquiring unit 11 (step S2 ). In step S2, for example, intermediate image processing such as background color change processing may be performed on the image data D by the ASIC 10 for image processing.

Next, the image formation control unit 16 refers to the management unit 17 to determine whether the pattern mode permission setting has been set for a user who is allowed to log in (hereinafter referred to as a logged-in user), that is, whether the logged-in user is allowed to execute the monochrome pattern mode ( Step S3).

And, when the setting to allow execution of the monochrome pattern mode is not made for the logged-in user ("No" in step S3), the image formation control unit 16 performs the processing of step S22 (see FIG. 8 ) to check whether the logged-in user is is an unlimited user.

On the other hand, when a setting is made to allow execution of the monochrome pattern mode for the logged-in user (YES in step S3), the image formation control unit 16 proceeds to step S4, and causes the frequency distribution acquisition unit 12 and the color setting unit 13 to perform, for example, Processing as described below.

In addition, although it is shown in FIG. 5 that the image forming control section 16 does not matter whether the logged-in user is a user limited to the monochrome mode or an unrestricted user, as long as the login user has made a setting to allow execution of the monochrome pattern mode, the process proceeds to step S4. However, the image formation control unit 16 may proceed to step S4 only when the logged-in user is a user limited to the black-and-white mode and a setting is made for the logged-in user to allow execution of the monochrome pattern mode.

The frequency distribution acquisition unit 12 counts the number of appearances of each color for each pixel of the image data D (step S4 ). Then, the frequency distribution acquisition unit 12 acquires a frequency distribution indicating the number of appearances of each color by using the colors of the pixels in the image data D as each group (step S5 ).

Next, the color setting unit 13 sets the first color (for example, white) that appears most frequently in the frequency distribution obtained in step S5 as the background color (step S6 ), and sets the second most frequently occurring color That is, the second color (such as black, gray, dark blue, etc.) is set as the color of the text (step S7). Then, the color setting unit 13 extracts the color having the third appearance number in the frequency distribution as the third color, and the color having the fourth appearance number as the fourth color (step S8 ).

Next, the color setting unit 13 sets the third color as a candidate design color of the logo L (step S9 ), and performs the processes after step S10 shown in FIG. 6 .

When the difference between the sum of the number of appearances of the first color that is estimated to be the background color and the number of appearances of the second color that is estimated to be the color of the text, and the total number of pixels of the color image is large, that is, the number of appearances is less than When the number of occurrences of the color of the second color is large, it can be inferred that the area of the specific pattern whose color belongs to the color system is large. When the area where the color belongs to a specific pattern having a color system is large, the consumption of color toner required to print the specific pattern is large.

Since the price of color toner is higher than that of black toner, when the difference between the sum of the number of appearances of the first color and the number of appearances of the second color and the total number of pixels of the color image is large, if a single If you choose the color pattern mode to print that particular pattern in color, it will increase the printing cost.

On the other hand, when the difference between the sum of the number of occurrences of the first color and the number of occurrences of the second color and the number of full pixels of the color image is small, that is, when the number of occurrences of colors less than that of the second color is less , it can be inferred that the area of the specific pattern whose color belongs to the color system is relatively small. If the area where the color belongs to a specific pattern having a color family is small, the consumption of the color toner required to print the specific pattern is not much. Therefore, when the difference between the sum of the number of appearances of the first color and the number of appearances of the second color and the total number of pixels of the color image is small, even if the monochrome pattern mode is executed to print the specific pattern in color, the printing cost is low. There won't be a big improvement.

Therefore, when the difference between the sum of the number of appearances of the first color and the number of appearances of the second color and the total number of pixels of the color image is small, it can be inferred that the area of the color belonging to a specific pattern with a color system is small, regardless of Regardless of whether the logged-in user is limited to a black-and-white mode user or an unrestricted user, the logged-in user is allowed to perform image formation in a monochrome pattern mode, so that the logo L that is important to the user can be faithfully reproduced on the recording paper. Color, and the color of underlined and colored parts, etc. As a result, user satisfaction can be improved within a range in which the cost increase due to the use of color toners during printing is not large.

From the viewpoint described above, the color setting unit 13 calculates the sum ( SUM1 ) of the number of appearances of the first color and the number of appearances of the second color (step S10 ). Next, the color setting unit 13 obtains the difference (OTHERS) by subtracting SUM1 from the total number of pixels of the color image using the following formula 1 (step S11 ).

OTHERS=full pixel count-SUM1 Formula 1

Then, the color setting unit 13 judges whether or not OTHERS is larger than a predetermined size judgment value tf1 (step S12 ).

If OTHERS is smaller than the size judgment value tf1, it can be presumed that the color of the specific pattern, such as the logo L that appears less frequently than the second color, occupies a small area in the image data D.

Therefore, in step S12, when OTHERS is smaller than the size judgment value tf1 (YES in step S12), the color setting unit 13 judges that the size of the specific pattern is small, and proceeds to step S13.

On the other hand, when OTHERS is equal to or greater than size determination value tf1 (NO in step S12 ), color setting unit 13 outputs information indicating that OTHERS is greater than or equal to size determination value tf1 to image formation control unit 16 . When OTHERS exceeds the size judgment value tf1, it can be inferred that the area of the specific pattern is large. If the single-color pattern mode is used to print with color toner, the problem of cost increase will occur. Therefore, when OTHERS is greater than or equal to the size judgment value tf1, even if the login user is permitted to execute the monochrome pattern mode, the image formation control unit 16 does not execute the monochrome pattern mode, but proceeds to step S26 in order to select a print mode according to the color of the characters. .

When the monochrome pattern mode is not executed, it is preferable to implement the monochrome mode in which the entire image data D is printed with black toner from the viewpoint of reducing printing costs.

However, if the color of the characters belongs to the chromatic system, it is advisable to faithfully reproduce the colors of the characters with a color toner. Then, in step S26 , the image formation control unit 16 determines whether or not the second color estimated to be the color of the characters belongs to the achromatic system.

When the second color belongs to the achromatic system (YES in step S26 ), the image formation control unit 16 executes the black and white mode (step S28 ). On the other hand, when the second color belongs to the chromatic system (NO in step S26 ), the image formation control unit 16 executes the monochrome mode (step S27 ).

In the monochrome mode of step S27 , the characters (C) and the logo L are printed with the color toner as the second color. Accordingly, it is possible to faithfully reproduce the color of the characters.

In addition, if the sum (SUM2) of the number of occurrences of the first color, the number of occurrences of the second color, and the number of appearances of the third color is subtracted from the total number of pixels of the image data, the difference obtained is {(number of total pixels )-(SUM2)} is less than the pattern judgment value tf2, it can be inferred that the number of appearances of the fourth color, the number of appearances of the fifth color and the number of appearances of the sixth color are all low. At this time, there is a high possibility that the specific pattern is composed of the third color (that is, composed of a single color).

From this point of view, in step S13 , the color setting unit 13 calculates the sum ( SUM2 ) of the number of appearances of the first color, the number of appearances of the second color, and the number of appearances of the third color (step S13 ). Next, the color setting unit 13 subtracts SUM2 from the total number of pixels of the image data D, and determines whether {(the total number of pixels)-(SUM2)} is smaller than a predetermined pattern determination value tf2 (step S14).

Through this determination, when the {(total number of pixels)-(SUM2)} is smaller than the pattern determination value tf2 (YES in step S14), the color setting section 13 determines that the specific pattern is composed of a single color, and, In order to judge whether to execute the single-color pattern mode, the process proceeds to step S15 (refer to FIG. 7 ). And when the {(total number of pixels)-(SUM2)} exceeds the pattern judgment value tf2 ("No" in step S14), it is judged that the specific pattern includes a plurality of colors, and, in order to implement black and white mode or full color mode, the process proceeds to step S22 (see FIG. 8 ).

In step S15, the color setting unit 13 determines whether or not the number of appearances of the third color is equal to or greater than a predetermined reference number of times tf3. When the number of occurrences of the third color exceeds the reference number of times tf3, there is a high probability that the specific pattern composed of the third color (that is, composed of a single color) occupies a certain range in the image data D, and when the number of occurrences of the third color When the number of times is less than the reference number of times tf3, none of the third to sixth colors constitute a pattern, and are highly likely to be scattered in the image data D.

When the number of occurrences of the third color reaches the reference number of times tf3 or more ("Yes" in step S15), the color setting part 13 enters the processing of step S16 in order to continue to judge whether to implement the monochrome pattern mode, and when the third color When the number of occurrences is smaller than the reference number of times tf3, the color setting unit 13 proceeds to the processing of step S22 (see FIG. 8 ) in order to print in the black-and-white mode or the full-color mode.

In step S16, the color setting unit 13 judges whether or not the number of occurrences of the third color is smaller than a predetermined auxiliary size judgment value tf4. Wherein, the auxiliary size judgment value tf4>tf3.

When the number of occurrences of the third color is less than the auxiliary size judgment value tf4, it can be inferred that the image area of the specific pattern composed of a single color is small, and when the number of appearances of the third color reaches the auxiliary size judgment value tf4, it can be inferred The image area of a specific pattern composed of a single color is large.

When the number of occurrences of the third color is smaller than the auxiliary size judgment value tf4 (YES in step S16 ), the color setting unit 13 judges whether the second color belongs to the achromatic system (step S17 ). When it is judged that the second color belongs to the achromatic system ("Yes" in step S17), the color setting part 13 sets the single-color pattern mode (step S18), and sets the third color as the pattern color (step S19 ). As a result, when printing an image including a pattern whose color belongs to a chromatic system, the color reproducibility of the pattern can be improved.

In addition, it is determined whether the second color belongs to the achromatic system in the process of step S17 , because when the second color belongs to the achromatic system, it can be presumed that the character (C) is black.

When the monochrome pattern mode is executed, the characters (C) are printed with black toner, so if the characters (C) are black, no problem occurs. However, if the color of the character C belongs to the color system, it is not appropriate to implement the monochrome pattern mode to print the character (C) with black toner. Therefore, when it is determined in step S17 that the second color belongs to the achromatic system (NO in step S17 ), the color setting unit 13 proceeds to step S22 in order to perform the full-color mode.

However, it is not necessarily necessary to judge whether it belongs to the achromatic system in step S17. For example, if it is known that the color of the character (C) is black without making the judgment in step S17, step S17 can be omitted.

When the monochrome pattern mode and the pattern color are set, the color setting unit 13 notifies the image formation control unit 16 that the monochrome pattern mode is set and that the third color is set as the pattern color of the specific pattern.

Next, the image forming control unit 16 executes the single-color pattern mode (step S20), prints the pattern using the toner of the pattern color set by the color setting unit 13, and uses the toner of the second color, for example, black tone. toner to print text (C).

After the image forming apparatus 1 completes the process of step S20 , it updates the billing information of the user (step S21 ). For example, the image forming apparatus 1 records, in the management unit 17, the amount charged to the user according to the user's identification information (the amount is used as the charging information), and after performing image formation in the monochrome pattern mode, the The amount of money corresponding to the pattern is sequentially recorded in the management unit 17 as charging information corresponding to the user identification information.

In this way, since the amount corresponding to the single-color pattern mode is sequentially recorded as charging information, it is easy to know how much the user is charged.

On the other hand, in step S16, when the number of occurrences of the third color exceeds the auxiliary size judgment value tf4 ("No" in step S16), the color setting unit 13 may charge the user in order to avoid the amount of money that can be charged to the user is not large. If a large amount of high-priced color toner is used in the single-color pattern mode, the process proceeds to step S22.

Also, in step S3, when the logged-in user is not permitted to execute the monochrome pattern mode (NO in step S3), the color setting unit 13 proceeds from step S3 to step S22 (see FIG. 8 ).

In addition, in step S14, when the value of {(total number of pixels)-(SUM2)} exceeds the pattern determination value tf2 ("No" in step S14), the color setting unit 13 uses black-and-white mode or full-color mode Printing is performed, and the process proceeds to step S22 (see FIG. 8 ). This is because when the value of {(total number of pixels)-(SUM2)} exceeds the pattern judgment value tf2, it can be inferred that the number of appearances of the fourth color, the number of appearances of the fifth color and the number of appearances of the sixth color are all lower. High, that is, the pattern is more likely to include multiple colors.

In addition, in step S15, when the number of occurrences of the third color is less than the reference number of times tf3 ("No" in step S15), the color setting unit 13 proceeds to step S22 (refer to FIG. 8) Processing. When the number of occurrences of the third color is less than the reference number of times tf3, the third color does not constitute a pattern, and the possibility that the third to sixth colors are scattered into the image data D is high. At this time, the image data D is not suitable for forming an image in the single-pattern mode in which only a specific pattern is printed in color, so the process proceeds to step S22.

In addition, in step S16, when the number of occurrences of the third color exceeds the auxiliary size judgment value tf4 ("No" in step S16), the color setting unit 13 also enters the Processing of step S22 (see FIG. 8 ). This is because when the number of occurrences of the third color is equal to or greater than the auxiliary size judgment value tf4, the color is estimated to be the third color and the area of the pattern image is likely to be large.

Next, the processing of steps S22 to S24 will be described using FIG. 8 .

In step S22 , if the user logged into image forming apparatus 1 is not a user who is allowed to execute the full-color mode (NO in step S22 ), the color setting unit 13 sets the black and white mode (step S24 ).

In the black and white mode, the image formation control section 16 prints the image data D using only black toner.

On the other hand, when the user logged into the image forming apparatus 1 is a user who is allowed to execute the full-color mode (YES in step S22 ), the color setting unit 13 sets the full-color mode (step S23 ).

In the full-color mode, the image formation control section 16 prints the image data D using toners of all colors.

Next, the image formation control unit 16 updates the billing information of the user (step S25 ). For example, the image forming apparatus 1 prepares in advance to record the amount charged to the user according to the user's identification information in the management unit 17 (the amount is used as the charging information), and the image forming is performed in the single-color pattern mode or the full-color mode. Thereafter, the amount corresponding to the executed mode is sequentially recorded in the management unit 17 as charging information corresponding to the user identification information.

In this way, since the amount corresponding to the black-and-white mode or the full-color mode to be executed is sequentially recorded as charging information, it is easy to know how much the user is charged.

In addition, after the color setting unit 13 sets the third color as the candidate design in step S9, it may not perform the processing of steps S10 to S12 and step S15, but directly perform the processing of steps S13, S14, S17, S18 and S19. process to set the third color as the pattern color.

In addition, the color setting unit 13 may perform the processing of steps S100 to S102 shown in FIG. 9 instead of the processing of steps S13 and S14 (see FIG. 6 ). FIG. 9 is a flowchart showing another example of processing performed by the color setting unit 13 .

If the difference obtained by subtracting the number of appearances of the first color, the number of appearances of the second color, the number of appearances of the third color and the number of appearances of the fourth color from the total number of pixels of the color image is less than the pattern judgment value tf5, Then, colors other than the first to fourth colors, such as the fifth and sixth colors, appear less frequently, and the color of the design is more likely to be the third or fourth color.

Furthermore, if the number of occurrences of the fourth color is smaller than the additional pattern determination value tf6, it is highly likely that the specific pattern is composed of the third color (that is, composed of a single color).

Therefore, the color setting unit 13 calculates the sum of the number of appearances of the first color, the number of appearances of the second color, the number of appearances of the third color, and the number of appearances of the fourth color after performing the processing of step S12 (see FIG. 6 ). (SUM3) (step S100). Next, the color setting unit 13 subtracts SUM3 from the total number of pixels of the image data D, and determines whether {(the total number of pixels)-(SUM3)} is smaller than a predetermined pattern determination value tf5 (step S101 ).

When the {(total number of pixels)-(SUM3)} is less than the pattern judgment value tf5 ("Yes" in step S101), the color setting unit 13 judges whether the number of occurrences of the fourth color is less than the predetermined additional pattern judgment value tf6 (step S102).

On the other hand, when the {(total number of pixels)-(SUM3)} reaches the pattern judgment value tf5 or more ("No" in step S101), the color setting unit 13 judges that the specific pattern includes a plurality of colors, and, in order to Print in full-color mode (or black-and-white mode), and proceed to step S22 (see FIG. 8 ). This is because when the above {(total number of pixels)-(SUM3)} exceeds the pattern judgment value tf5, it is highly likely that the pattern consists of a plurality of colors.

In step S102, when the number of occurrences of the fourth color is less than the additional pattern judgment value tf6 ("Yes" in step S102), the color setting part 13 performs the processing of step S19 through steps S15 to S18, and sets the third color for the pattern color. As described above, through the processing of steps S100 to S102, it is possible to reduce the possibility that the third color is erroneously set as the pattern color of a specific pattern including a plurality of colors. As a result, when an image including a pattern whose color belongs to a chromatic system is printed, the color reproducibility of the pattern can be improved.

In addition, the image forming apparatus 1 may not have the management unit 17 , the operation input unit 18 , and the setting unit 20 , and may perform the following operations without performing steps S1 , S3 , S9 to S12 , S15 to S18 , and S20 to S28 .

For example, the image forming apparatus 1 may sequentially perform steps S2, S4 to S8, S13, and S14, and if YES in step S14, proceed to step S19 to set the third color as the design color. In addition, if "NO" in step S14, steps S22 to S25 may also be performed.

As a result, when an image including a pattern whose color belongs to a chromatic system is printed, the color reproducibility of the pattern can be improved.

In addition, steps S100 to S102 can also be used instead of steps S13 and S14, that is, steps S2, S4 to S8, and S100 to S102 are performed in sequence, and if "Yes" in step S102, then step S19 is performed to set the third color for the pattern color. Thereby, it is possible to reduce the possibility that the third color is erroneously set as the pattern color of a specific pattern including a plurality of colors. As a result, when an image including a pattern whose color belongs to a chromatic system is printed, the color reproducibility of the pattern can be improved. In the following description, steps S100 to S102 may be similarly performed instead of steps S13 and S14.

In addition, steps S2, S4 to S8, S13, and S14 can also be performed in sequence, and if it is "Yes" in step S14, then step S16 is performed, and, when it is "Yes" in step S16, step S19 is performed so that the third color Set as pattern color. In this way, the design color is not set for a large design that consumes a large amount of color toner, but only the third color is set as the design color for a small design that is not expensive to print. Therefore, it is possible to easily reduce the printing cost. Improve user satisfaction within the allowable range.

In addition, the image forming control unit 16 proceeds from step S3 to step S4 only when the logged-in user is a user limited to the black-and-white mode and the logged-in user has made a setting to allow execution of the monochrome pattern mode. 1 It is also possible not to carry out steps S9 to S12, S15 to S18, S21, S22, S23 and S25, but to carry out steps S1 to S8, S13 and S14 in sequence, and if "Yes" in step S14, to carry out steps S19 and S20, thereby Image formation is performed in monochromatic pattern mode, and if "No" in step S14, proceed to step S24, thereby performing image formation in black and white mode.

At this time, when the identification information input unit accepts the input of the identification information of the user limited to the black and white mode, and the setting unit accepts the setting of allowing the monochrome pattern mode to be executed by the user having the identification information, the user limited to the black and white mode is allowed to execute the pattern. Black and white mode and monochrome pattern mode. In this way, by setting the monochromatic pattern mode to be allowed to be executed, it is possible to improve the user's satisfaction within a range in which the cost burden is not greatly increased.

In addition, in step S102, when the number of appearances of the fourth color is less than the additional pattern determination value tf6 (YES in step S102), the color setting unit 13 may not perform steps S15 and S16 (refer to FIG. 7 ). The processing is to set the single-color pattern mode (step S18), and set the third color as the pattern color (step S19).

In addition, the color setting unit 13 may perform the processing of step S100 not after the processing of step S12 (see FIG. 6 ), but after the processing of step S9 (see FIG. 5 ).

On the other hand, when the number of appearances of the fourth color reaches the additional pattern judgment value tf6 or more ("No" in step S102), the color setting part 13 proceeds to step S22 (refer to FIG. 8) Processing. This is because when the number of occurrences of the fourth color exceeds the additional pattern judgment value tf6, the pattern is more likely to include a plurality of colors.

In addition, in the above processing, the image formation control unit 16 executes the monochrome mode, the monochrome mode, the monochrome pattern mode, and the full-color mode, but it is not necessary to execute all the modes, as long as the monochrome mode and the monochrome pattern mode are executed.

Next, the details of the setting process of the background color, the character color, and the pattern color will be described with reference to FIGS. 10 to 14 . FIG. 10 is an explanatory diagram showing an example of three-dimensional frequency distribution information representing a frequency distribution generated by the frequency distribution acquisition unit 12 in FIG. 2 . However, the frequency distribution acquisition unit 12 may generate the frequency distribution as a two-dimensional frequency distribution graph.

The color (pixel value) of each pixel of the image data D is expressed by the density values of three element colors. When the density value of cyan is c, the density value of magenta is m, and the density value of yellow is ye, the density value of each pixel is Color (pixel value) can be expressed as (c,m,ye)

Then, as shown in FIG. 10, when the density values of cyan (C), magenta (M) and yellow (Y) are assigned to the respective coordinate axes of the three-dimensional coordinates, the color (group) image of each pixel is The cuboid G in FIG. 10 is arranged on the three-dimensional coordinates like this. By associating the cuboids (groups) arranged on the three-dimensional coordinates with the frequencies, three-dimensional frequency distribution information represented by a three-dimensional frequency distribution graph can be generated.

In this way, the frequency distribution acquisition unit 12 arranges the frequency distribution on the three-dimensional coordinates to generate three-dimensional frequency distribution information.

In Fig. 10, the density value of cyan (C) is assigned to the X-axis extending in the left-right direction, the density value of magenta (M) is assigned to the Y-axis extending in the vertical direction, and the Z-axis extending in the direction of the paper surface Assign the concentration value of yellow (Y) on it.

The pixel value (c, m, ye) of each pixel is represented by a group (small cuboid G) arranged on the coordinates (X, Y, Z).

The density value of each element color is represented by 8 bits, and can be converted into Hx00 to HxFF in hexadecimal notation. Hereinafter, Hx is appended to represent a hexadecimal number. In FIG. 10 , each coordinate axis shows only the upper-order 4 digits of the density value of each element color. That is, the density value of each element color is represented by Hx0 to HxF.

At this time, on the three-dimensional coordinates where the value of each coordinate axis is the upper order 4 bits, for example, the group (small cube G) represented by the coordinates (HxF, HxF, HxF) actually includes the range of pixel values in (HxF0 to HxFF, HxF0 to HxFF, HxF0 to HxFF) in multiple colors. Also, the range of the lower-order 4 digits Hx0 to HxF of each density value corresponds to the range of each divided group.

Hereinafter, a group (cuboid) G including a plurality of colors is referred to as a color group G. FIG. A color group G is a group including all colors in the color group G. The sum of pixels of all colors included in the color group G corresponds to the number of appearances (frequency) of the color group G. Hereinafter, a plurality of colors included in the color group G, that is, a plurality of colors that share a higher order in the density value are referred to as colors of the color group G.

As described above, the frequency distribution acquisition unit 12 assigns the upper 4 digits of the cyan density value to the X coordinate, the upper 4 digits of the magenta density value to the Y coordinate, and the upper 4 digits of the yellow density value to the Z coordinate. bit.

As a result, the frequency distribution acquisition unit 12 arranges the colors that share the upper 4 digits of the density values of the respective element colors (cyan, magenta, and yellow) as a color group (group) on the three-dimensional coordinates.

However, the frequency distribution acquisition unit 12 does not necessarily need to allocate the upper 4 digits on the coordinate axis, and may arrange several upper order digits other than the upper 4 digits. In addition, the frequency distribution acquisition unit 12 may allocate all the digits of each density value on each coordinate axis. At this time, one color group (group) G represents one color, that is, one color is equivalent to one group.

Next, an example when the image forming apparatus 1 performs processing using color groups will be described.

The frequency distribution acquisition unit 12 , the color setting unit 13 and the image formation control unit 16 replace each color with each color group and replace the appearance number of each color with the appearance number of each color group in steps S4 to S16 . At this time, the color groups are set as the first color group G (1), the second color group G (2), the third color group G (3), and the fourth color group G in order of the number of occurrences from high to low. (4), and the fifth color group G (5), wherein the color of the first color group G (1) is the first color, the color of the second color group G (2) is the second color, and the third color group G The color of (3) is the third color, the color of the fourth color group G (4) is the fourth color, and the color of the fifth color group G (5) is the fifth color.

In step S5 , the frequency distribution acquisition unit 12 acquires a frequency distribution indicating the number of appearances of each color group by using each color group as a group. Thereby, the amount of processing performed by the frequency distribution acquisition unit 12 can be reduced compared to the case of acquiring the frequency distribution in the case of expressing the density value of each color with 8 bits.

In step S6 , the color setting unit 13 sets the color that appears most frequently among the colors of the first color group G( 1 ) that appears most frequently, that is, the first color, as the background color.

In step S7 , the color setting unit 13 sets the color with the highest number of appearances as the color of the characters among the colors of the second color group G( 2 ) with the second highest number of appearances, that is, a plurality of colors as the second color.

In steps S17 and S26, the color setting unit 13 judges whether or not the color that appears most frequently among the second colors belongs to the achromatic system.

In step S19 , the color setting unit 13 sets the color with the largest number of occurrences among the colors of the third color group G( 3 ), that is, the third color, as the pattern color.

Next, an example of processing for specifying a pattern color using a color group will be described in more detail. FIG. 11 is an explanatory diagram schematically showing a structural example of a group aggregate to which the first color group G( 1 ) and the second color group G( 2 ) belong.

In step S8, the color setting unit 13 may also set the third color and the fourth color as follows. Specifically, as shown in FIG. 11 , based on the three-dimensional frequency distribution information shown in FIG. Groups (ie, color groups) to a predetermined judgment distance form a group aggregate S(1).

In addition, as shown in FIG. 11 , the color setting unit 13 selects the second color group G(2) and the group whose distance to the coordinate position of the second color group G(2) is less than a predetermined judgment distance (that is, the color group) Form a cluster aggregate S(2).

For example, the color setting unit 13 makes the first color group G(1) included in one group aggregate S(1) and the Euclidean distance (euclidean distance) to the coordinate position of the first color group G(1) be smaller than The color group on the coordinates of 2.

For example, the color setting unit 13 makes the second color group G(2) included in one group aggregate S(2) and the Euclidean distance (euclidean distance) to the coordinate position of the second color group G(2) be smaller than The color group on the coordinates of 2.

In the three-dimensional coordinates shown in Figure 10 and Figure 11, the coordinates (X, Y, Z) of the first color group G (1) are set as coordinates a (a1, a2, a3), arbitrary coordinates (X, Y, Z ) is the coordinate b (b1, b2, b3), the Euclidean distance between these two coordinates can be expressed by the following formula 2.

$d(a,b)=\sqrt{\underset{i=1}{\overset{3}{\mathrm{\Σ}}}{(a_i-b_i)}^2}$ Formula 2

where d(a,b) represents the Euclidean distance between coordinate a and coordinate b.

Fig. 12 is a perspective view schematically showing a structural example of a cluster aggregate. Fig. 13 is an exploded perspective view schematically illustrating a structural example of a cluster assembly. 12 and 13 show structural examples of the cluster aggregate S(1). Since the structure of the cluster aggregate S(2) is the same as that of the cluster aggregate S(1), illustration and description are omitted.

As shown in Figure 12 and Figure 13, the group aggregate S(1) consists of the first color group G(1), and the color group G(11) (hereinafter referred to as the second One adjacent color group), and the color group G(12) which is not in contact with the first color group G(1) by points but contacts with the first color group G(12) (hereinafter referred to as the second adjacent color group).

In Figure 12 and Figure 13, the first color group G (1) is shown in dotted line, the first adjacent color group G (11) is shown in white, and the second adjacent color group G (12) is shown in color out.

In this group aggregate S(1), both the first adjacent color group G(11) and the second adjacent color group G(12) are located at a distance less than 2 to the first color group G(1). coordinates.

The color setting section 13 adds the number of appearances of the first adjacent color group G (11) and the number of appearances of the second adjacent color group G (12) to the first color group G (1) in the group aggregate S (1). ), and store the obtained number of appearances as the number of appearances of the first color group G(1) in a register or the like not shown in the figure.

In addition, the color setting unit 13 also adds the number of appearances of the first adjacent color group and the number of appearances of the second adjacent color group to the second color group similarly to the group assembly S(1) for the group aggregate S(2). The number of appearances of G(2) is calculated, and the obtained number of appearances is stored in a register not shown in the figure as the number of appearances of the second color group G(2).

In addition, the color setting unit 13 may remove a predetermined group of colors from the three-dimensional coordinates, and set the color (color group) that appears second only to the second color group G(2) in the remaining area as The third color, wherein the specified group is not only a group arranged in the path formed by connecting the group aggregate S(1) and the group aggregate S(2) with a straight line, but also a group on the three-dimensional coordinates to the first color group A group whose distance from G( 1 ) is greater than a predetermined judgment distance (for example, greater than Euclidean distance 2 ) and whose distance to the second color group G( 2 ) is greater than the judgment distance.

For example, as shown in FIG. 11 , the color setting unit 13 connects the group aggregate S(1) to which the first color group G(1) belongs and the cluster aggregate S(2) to which the second color group G(2) belongs with a straight line, Thus, a cuboid-shaped region A including the cluster aggregate S( 1 ) and the cluster aggregate S( 2 ) is formed (see FIG. 11 ). Next, the color setting unit 13 removes the cluster aggregate S( 1 ) and the cluster aggregate S( 2 ) from the area A to obtain the area A( 1 ). Next, the color setting unit 13 obtains the color (color group) that appears second only to the second color group G(2) in the remaining region after removing the region A(1) from the three-dimensional coordinates as the third color .

However, the color setting unit 13 may use the first color group G(1) and the second color group G(2) instead of the group aggregate S(1) and the cluster aggregate S(2) in step S8, and connect them with a straight line. The first color group G(1) and the second color group G(2) form a cuboid-shaped area A including the first color group G(1) and the second color group G(2), and are removed from the area A The groups (colors) whose distance to the first color group G(1) is smaller than the judgment distance on the three-dimensional coordinates and the groups (colors) whose distance to the second color group G(2) is smaller than the judgment distance, thereby obtaining Area A (1). Next, the color setting unit 13 may set the color (color group) that appears second only to the second color group G(2) as the third color in the remaining region after removing the region A(1) from the three-dimensional coordinates. color.

In addition, the color setting unit 13 may use the first color and the second color instead of the cluster aggregate S(1) and the cluster aggregate S(2) in step S8, and connect the first color and the second color with a straight line to form a A linear region A of the first color and the second color, from which a group (color) whose distance to the first color is smaller than the judgment distance on three-dimensional coordinates and a group (color) whose distance to the second color is smaller than the judgment distance is removed Group of distances (colors) to obtain area A (1). Then, the color setting unit 13 can remove the remaining area of the area A(1) from the three-dimensional coordinates, and set the color whose appearance frequency is second only to the second color as the third color.

The color setting unit 13 obtains the third color group G(3) whose appearance frequency is second only to the second color group G(2) from the three-dimensional coordinates of the excluded area A(1), and obtains the third color group G(3) whose appearance frequency is second only to the third color group G(2). The fourth color group G(4) of the color group G(3).

In addition, in the three-dimensional coordinates after removing the area A (1), if there is a color group that appears less than the fourth color group G (4), for example, the fifth color group G (5) (see FIG. 10 ) and the occurrence The color setting unit 13 also obtains the sixth color group G( 6 ) (see FIG. 10 ) whose frequency is smaller than that of the fifth color group G( 5 ).

In addition, in step S10, the color setting unit 13 may also use the number of appearances of the first color and the number of appearances of the second color obtained from the first color group G(1) and the second color group G(2) to calculate SUM1.

In addition, in step S13, the color setting unit 13 may also use the number of occurrences of the first color obtained from the first color group G(1), the second color group G(2) and the third color group G(3) , the number of occurrences of the second color and the number of occurrences of the third color to calculate SUM2.

In addition, in step S100, the color setting unit 13 can also use the first color group G(1), the second color group G(2), the third color group G(3) and the fourth color group G(4) ) to calculate SUM3 by obtaining the number of occurrences of the first color, the number of occurrences of the second color, the number of occurrences of the third color, and the number of occurrences of the fourth color.

In addition, in step S15 , the color setting unit 13 may compare the appearance count of the third color obtained from the third color group G( 3 ) with the reference count tf3 .

In addition, in step S16 , the color setting unit 13 may compare the number of occurrences of the third color obtained from the third color group G( 3 ) with the auxiliary size determination value tf4 .

In addition, when the monochromatic pattern mode is set, the color setting unit 13 performs, for example, the following processing together with the frequency distribution acquiring unit 12 . Through the following process, from the colors of the third color group G( 3 ) (ie, the third color including a plurality of colors), the color that appears most frequently is set as the pattern color.

FIG. 14 is a conceptual explanatory diagram for explaining the processing performed by the frequency distribution acquisition unit 12 and the color setting unit 13 when setting the monochrome pattern mode. In other words, FIG. 14 is a diagram for explaining an example of processing in which the color setting unit 13 sets, in step S19 , the color that appears most frequently among the colors included in the third color as the design color.

Figure 14(a) shows that the upper 4 digits of the density value of cyan (C), the upper 4 digits of the density value of magenta (M), and the upper 4 digits of the density value of yellow (Y) respectively correspond to X Axis, Y-axis, Z-axis three-dimensional coordinates. Fig. 14(b) shows a plurality of colors belonging to the third color group G(3).

In Fig. 14(b), a plurality of colors belonging to the third color group G(3) are shown in small squares, such as color CO(1), color CO(2), color CO(3), color CO( 4) and the color CO(5).

For cyan (C), magenta (M) and yellow (Y), the frequency distribution acquisition unit 12 expresses upper-order three-dimensional coordinate information ( FIG. 14( a )) on the X-axis, Y-axis, and Z-axis. As shown in Figure 14(b), the lower four digits (Hx0 to HxF) of the basic digits of the cyan (C) density value are further represented by the X-axis, and the basic digits of the magenta (M) density value are represented by the Y-axis The lower order 4 digits (Hx0 to HxF) in the number, and use the Z axis to represent the lower order 4 digits (Hx0 to HxF) in the basic digits of the yellow (Y) concentration value.

Then, the frequency distribution acquisition unit 12 sets the lower 4 bits of the cyan (C) density value, the lower 4 bits of the magenta (M) density value, The lower four digits of the yellow (Y) density value correspond to the X-axis, Y-axis, and Z-axis, respectively, and these multiple colors are arranged on the three-dimensional coordinates shown in FIG. 14( b ).

The color setting unit 13 obtains the number of occurrences of colors arranged on three-dimensional coordinates (for example, colors CO(1) to CO(5)) from the third color group G(3), and stores them in registers not shown in the figure, etc. middle. Then, the color setting unit 13 sets the color that appears most frequently in the three-dimensional coordinates shown in FIG. 14( b ), for example, color CO(1), as the pattern color of the specific pattern.

(Second Embodiment)

Next, an image forming apparatus according to a second embodiment of the present invention will be described. In the first embodiment, an example was shown in which the color reproducibility of a specific pattern such as a logo is improved in a single color, but in business documents, a logo is often composed of a plurality of colors belonging to a chromatic system. Moreover, it is not uncommon for a plurality of underlined or colored parts to be printed with a plurality of colors belonging to a color system.

Therefore, there is a need to improve the color reproducibility of a sign composed of a plurality of colors. Also, underlined or colored parts should not be set to a color different from the original color.

Therefore, the image forming apparatus 1a according to the second embodiment has a full-color pattern mode for printing specific patterns such as logos, underlines, and colored parts in full color.

The mechanical structure of the image forming apparatus according to the second embodiment is the same as that of the first embodiment, that is, shown in FIG. 1 . FIG. 15 is a block diagram showing an example of an electrical configuration of an image forming apparatus 1 a according to a second embodiment of the present invention.

The difference between the image forming apparatus 1 a shown in FIG. 15 and the image forming apparatus 1 shown in FIG. 2 is as follows. That is, the image forming apparatus 1a shown in FIG. 15 further includes an undercolor removal unit 104, a second setting unit 102, a third setting unit 103, a fourth setting unit 105, and a fifth setting unit 106; The ASIC 10a also has an image processing unit 120; the image formation control unit 16a (an example of the control unit) and the operation control unit 19a work differently from the image formation control unit 16 and the operation control unit 19; the pattern mode permission setting in the management unit 17a Different from the management unit 17, that is, information indicating whether the single-color pattern mode or the full-color pattern mode is allowed is stored in the management unit 17a; and the image forming apparatus 1a also has a first setting unit 101 instead of the setting unit 20 .

The other configurations of the image forming apparatus 1 a are the same as those of the image forming apparatus 1 shown in FIG. 2 , so description thereof will be omitted. The features of this embodiment will be described below.

The image processing unit 120 performs predetermined image processing on the image data acquired by the image data acquiring unit 11 . For example, the image processing unit 120 performs the background color changing process.

The difference between the color setting part 100 and the color setting part 13 is that: the color setting part 100 sets all colors according to the number of occurrences of the first color, the second color, and the color whose number of occurrences is less than the second color. Color pattern mode, and use the color that appears less than the second color to set the color of a specific pattern in the color image (that is, the pattern color).

The details of the processing of the color setting unit 100 will be described later.

The difference between the image formation control unit 16a and the image formation control unit 16 is that the image formation modes of the image formation control unit 16a include the full-color pattern mode in addition to the black and white mode, the monochrome mode, the full-color mode and the monochrome pattern mode. Also, if the user limited to the monochrome mode is allowed to execute the full-color pattern mode described later, the image formation control unit 16 a allows the user limited to the monochrome mode to execute the full-color pattern mode in addition to the monochrome mode. The rest of the structure of the image formation control unit 16a is the same as that of the image formation control unit 16, and therefore description thereof will be omitted.

In the management unit 17a, in addition to the same information as the management unit 17, information indicating whether the single-color pattern mode or the full-color pattern mode is permitted is stored as the pattern mode permission setting. That is, in the following description, "there is a pattern mode permission setting" means that the single-color pattern mode or the full-color pattern mode is allowed to be executed. However, the management unit 17a may store information indicating that only the full-color pattern mode is permitted as the pattern mode permission setting.

In addition to the same operations as the operation control unit 19, the operation control unit 19a outputs signals corresponding to the operation instructions accepted by the operation input unit 18 to the first setting unit 101, the second setting unit 102, the third setting unit 101, and the third setting unit 101. The fixed part 103 , the fourth setting part 105 and the fifth setting part 106 .

The difference between the first setting part 101 and the setting part 20 is that: the first setting part 101 not only outputs a signal for requesting to be set to allow the implementation of the single-color pattern mode when the operation control part 19a outputs, but also When outputting a signal for requesting the permission setting of the full-color pattern mode, the information indicating the permission setting of the pattern mode is associated with the identification information of the user who is allowed to execute the pattern mode, and stored in the management unit 17a. Other configurations of the first setting unit 101 are the same as those of the setting unit 20 . Thus, the first setting unit 101 sets the pattern mode permission. Hereinafter, the single-color pattern mode and the full-color pattern mode are collectively referred to as pattern mode.

When the operation input unit 18 accepts setting of the size judgment value tf1 , the second setting unit 102 outputs the size judgment value tf1 to the color setting unit 100 and sets it in the color setting unit 100 .

When the operation input unit 18 accepts the setting of the reference ratio, the third setting unit 103 outputs the reference ratio to the color setting unit 100 and sets it in the color setting unit 100 .

The fourth setting unit 105 outputs the plurality of color determination values tf12 to the color setting unit 100 when the operation input unit 18 accepts setting of the plurality of color determination values tf12 and sets them in the color setting unit 100 .

As will be described later, it is determined whether to set the full-color pattern mode according to whether the number of occurrences of the fourth color is greater than or smaller than the plurality of color judgment values tf12 or less. With the fourth setting section 105 for setting a plurality of color determination values tf12, the user can easily set the number of occurrences of the fourth color to set the image forming mode to the full-color pattern mode.

The fifth setting unit 106 outputs the additional plurality of color determination values tf13 to the color setting unit 100 when the operation input unit 18 accepts setting of the additional plurality of color determination values tf13, and sets them in the color setting unit 100. .

As will be described later, according to whether the difference between the total number of pixels of the image and the sum of the number of appearances of the first color to the number of appearances of the fourth color is greater than or greater than the additional multiple color judgment value tf13 or is smaller than the additional multiple color judgment value tf13, to determine whether to set the full-color pattern mode. Since there is the fifth setting section 106 for setting and adding a plurality of color judgment values tf13, the user can easily set the difference between the total number of pixels of the image and the sum of the number of appearances of the first color to the number of appearances of the fourth color To what extent, the image forming mode is set to the full-color pattern mode.

In a normal state, that is, when the full-color pattern mode is not set, when the image forming unit 40 prints an image based on the image data D, the undercolor removal unit 104 performs UCR (undercolor removal) processing. The UCR process is a process of converting, for each pixel of the image data D, a portion corresponding to gray among the density values of cyan, magenta, and yellow into black.

The undercolor removal unit 104 may convert, for each pixel of the image data, a portion corresponding to gray among the density values of red, green, and blue into black.

On the other hand, when the image data is printed by the image forming unit 40 in the state where the full-color pattern mode is set, the undercolor removing unit 104 converts the second color estimated to be the color of the characters into black to perform 100% UCR. deal with.

Next, the operation of the image forming apparatus 1 a will be described using FIGS. 16 to 18 . 16 to 18 are flowcharts showing an example of the operation of the image forming apparatus 1a. In the following work flow, the difference between the image forming apparatus 1a and the image forming apparatus 1 is that the main body of work is changed from the image processing ASIC 10, the color setting part 13, the image forming control part 16 and the management part 17 to the image processing ASIC 10a, Color setting unit 100, image formation control unit 16a, and management unit 17a assign the same step numbers to the same operations as those in the flowcharts shown in FIGS. 5 to 9, and descriptions thereof are omitted.

In addition, in the following description, it is assumed that the color of the background B is the first color, and the color of the character C is the second color. Also, the logo L includes four colors of the third color, the fourth color, the fifth color, and the sixth color that appear less frequently than the second color in the image data D.

First, the same processing as steps S1 and S2 in FIG. 5 is performed in steps S1 and S2. At this time, it is assumed that the identification information of the user registered in step S1 is stored in the management unit 17a in advance as a user limited to the monochrome mode. Hereinafter, the processing performed for the user limited to the monochrome mode will be described using the flowcharts shown in FIGS. 16 to 18 .

The image formation control section 16a refers to the management section 17a, and judges whether the pattern mode permission setting has been made for the user who is limited to the black-and-white mode allowed to log in, that is, judges whether the logged-in user is allowed to execute the full-color pattern mode or the monochrome pattern mode (step S103).

Also, when the login user has not made the setting to allow execution of the pattern mode ("No" in step S103), the image formation control unit 16a executes the black and white mode, and prints the image data D using only black (K) toner ( Step S104).

Next, the image formation control unit 16 a updates the charging information of the user (step S105 ). For example, the image forming apparatus 1a prepares in advance to record in the management unit 17a the amount charged to the user according to the user's identification information (the amount is used as the charging information), and after performing image formation in the black-and-white mode, the The amount of money corresponding to the pattern is sequentially recorded in the management unit 17a as charging information corresponding to the user identification information.

In this way, since the amount corresponding to the executed monochrome mode is sequentially recorded as charging information, it is easy to know how much the user is charged.

On the other hand, when the pattern mode permission setting has been made by the logged-in user (YES in step S103 ), the image formation control unit 16 a proceeds to step S4 . If the image formation control unit 16a does not have the single-color pattern mode, in step S103, the image formation control unit 16a may proceed to step S4 when the login user is permitted to execute the full-color pattern mode. Next, steps S4 to S8 are performed as in FIG. 5 .

After performing step S8, the color setting unit 100 assumes a color that appears less frequently than the second color as the pattern color constituting the specific pattern, and proceeds to step S10. Then, the color setting unit 100 performs the processing of steps S10 to S12 similarly to FIG. 6 .

And, in step S12, when OTHERS is smaller than the size determination value tf1 (YES in step S12), the color setting unit 100 determines that the size of the specific pattern is small, and proceeds to step S114.

On the other hand, when OTHERS is equal to or greater than size determination value tf1 (NO in step S12 ), color setting unit 100 outputs information indicating that OTHERS is greater than or equal to size determination value tf1 to image formation control unit 16 a. When OTHERS exceeds the size judgment value tf1, it can be inferred that the area of the specific pattern is large, and if the pattern mode is executed to print with color toner, the problem of cost increase will occur. Therefore, when OTHERS exceeds the size judgment value tf1, even if the login user is permitted to execute the pattern mode, the image formation control unit 16a does not execute the pattern mode, and proceeds to step S26 in order to select a print mode according to the color of the characters. Next, steps S26 to S28 are performed in the same manner as in FIG. 6 .

In addition, the color setting unit 100 may determine whether the ratio {(SUM1)/(total number of pixels)} of the sum (SUM1) of the number of appearances of the first color and the number of appearances of the second color to the total number of pixels of the color image is If it is equal to or higher than a predetermined reference ratio, the processing of step S12 is replaced.

When the service provider sets that the larger the recording paper used for printing a specific pattern, the higher the printing fee charged to the user will be, and if the proportion of the specific image in the entire color image is less than the specified proportion, the color toner fee will be charged. The proportion of the entire printing cost is not large.

Therefore, when the ratio {(SUM1)/(total number of pixels)} exceeds the reference ratio, it can be inferred that the proportion of the specific pattern in the entire image is relatively small, so enter step S114 and execute the pattern mode, and when the ratio { (SUM1)/(total number of pixels)} is less than the reference ratio, it can be inferred that the proportion of the specific pattern in the entire image is relatively large, so go to step S26 and implement black and white mode or monochrome mode, and form according to each image The pattern is charged, so that the service provider can provide users with the service of printing a specific pattern using color toner without incurring a loss.

In step S114 , the color setting unit 100 determines whether or not the number of occurrences of the fourth color is equal to or greater than a predetermined plurality of color determination values tf12 (step S114 ). When the number of appearances of the fourth color is equal to or greater than a predetermined value, it can be estimated that the specific pattern is composed of a plurality of colors including at least the third color and the fourth color.

Therefore, the color setting unit 100 proceeds to step S115 when the number of occurrences of the fourth color is less than the multiple color determination value tf12 (YES in step S114), and proceeds to the processing of step S115 when the number of occurrences of the fourth color reaches a multiple of color When the determination value is greater than or equal to tf12 ("No" in step S114), the color setting unit 100 determines that the specific pattern includes a plurality of colors, and sets the full-color pattern mode (step S118).

For example, in the case where the multiple color judgment value tf12 is 1, in the example shown in FIG. The setting unit 100 determines that the mark L includes a plurality of colors, and sets the full-color pattern mode.

In step S115 , the color setting unit 100 calculates the sum of the number of appearances of the third color and the number of appearances of the fourth color ( SUM4 ).

In addition, the color setting unit 100 determines the value obtained by subtracting SUM4 from OTHERS acquired in step S11, that is, the sum obtained by subtracting the number of appearances of the first color to the number of appearances of the fourth color from the total number of pixels in the color image. Whether the value of is greater than or equal to the predetermined additional multiple color judgment value tf13 (step S116 ). Next, the reason for performing the process of step S116 will be described.

For example, in the case where the multi-color judgment value tf12 is 1, in the example shown in FIG. The determination unit 100 judges that the mark L is composed of a single color.

However, when the plurality of color determination value tf12 is 1, the number of occurrences of the flag color 2 (the fourth color) in the example shown in FIG. constitute. At this time, the logo L is a multicolor logo including a plurality of colors, but the logo L is misjudged to be composed of a single color.

Then, in order to reduce the possibility that a specific pattern including a plurality of colors is misjudged as a single-color pattern, the processing of step S116 is performed.

In step S116, the value obtained by subtracting the sum of the number of appearances of the first color to the number of appearances of the fourth color from the total number of pixels of the color image, that is, the sum of the appearance times of colors whose appearance times are below the fifth place is less than When a plurality of color determination values tf13 are added (YES in step S116 ), the color setting unit 100 determines that the specific pattern is composed of a single color, and sets a single color pattern mode (step S117 ).

In the example of a monochrome mark shown in FIG. 4B, "the sum of the number of occurrences of colors below the fifth digit" means the sum of the number of occurrences of the first color to the number of appearances of the fourth color subtracted from the total number of pixels of the color image. and the resulting value. For example, when adding a plurality of color judgment values tf13 is 1, since the "sum of the number of appearances of colors below the fifth place" shown in Figure 4B is 0.5, that is, "the sum of the number of appearances of colors below the fifth place" is 0.5. and" are smaller than the additional multi-color judging value tf13, so set the single-color pattern mode.

In step S114, when the number of appearances of the fourth color is less than a plurality of color judgment values tf12, and in step S116, the sum of the appearance times of colors below the fifth place is less than the addition of a plurality of color judgment values tf13, because The specific pattern is determined to be composed of a single color for the following reasons.

That is, when the specific pattern is composed of a single color, in the image data D read by the image reading unit 200, the pixels around the specific pattern may be read as a color similar to the color of the specific pattern due to the bleeding of the color of the specific pattern. pixels. In this way, the color produced by the bleeding of the color of a particular pattern becomes the fourth color. At this time, if in step S116, the sum of the number of appearances of the colors below the fourth place (that is, the colors including the fourth color) reaches more than the additional multiple color judgment value tf13, it is determined that the specific pattern includes more than one color. If there is only one color, the color caused by the bleeding of the color (tertiary color) of the specific pattern will be affected, resulting in the misjudgment of a specific pattern composed of a single color as a pattern containing multiple colors.

On the other hand, even if the number of occurrences of the fourth color in step S114 is less than the color judgment value tf12, the specific pattern may be composed of a lot of colors (maybe each color is used in a small amount). In this case, even if the number of appearances of the fourth color is a small value smaller than the multiple color judgment value tf12, the sum of the number of appearances of each color whose number of occurrences is below the fifth digit also reaches more than the additional multiple color judgment value tf13 large value.

Therefore, in step S116, when the sum of the appearance times of the colors below the fifth place (that is, not including the fourth color) reaches the additional multiple color judgment value tf13 or more, it is determined that the specific pattern includes multiple colors, thereby Improves the accuracy of judging whether a particular pattern consists of a single color or includes multiple colors.

When setting the monochrome pattern mode in step S117, the color setting section 100 sets only the third color as the pattern color of the specific pattern, notifies the image forming control section 16a that the monochrome pattern mode is set, and sets only the third color as the pattern color of the specific pattern. The third color is set as the pattern color of a specific pattern.

Next, the image forming control section 16a executes the monochrome pattern mode, prints a specific pattern using the toner of the pattern color set by the color setting section 100, and prints a pattern using toner of a second color, for example, black toner. Print text (C).

On the other hand, when the value obtained by subtracting the sum of the number of appearances of the first color to the number of appearances of the fourth color from the total number of pixels of the color image is equal to or greater than the predetermined number of additional color judgment values tf13 (in step S116: "No"), the color setting unit 100 sets the full-color pattern mode (step S118 ).

For example, when the judgment value tf13 of adding a plurality of colors is 1, in the example shown in FIG. Above, therefore set the full-color pattern mode.

When setting the full-color pattern mode (step S118 ), the color setting unit 100 sets all colors that appear less than the second color as pattern colors (step S122 ). For example, the color setting unit 100 sets all the third to sixth colors as pattern colors.

Then, the processing of steps S123 and S124 is performed by the image formation control unit 16a.

If the color of the character (C) in the image data D is a color other than black, in order to express the color of the character C, an expensive color toner is used, that is, a cyan toner, a magenta toner, and a yellow toner are used. Toner. In this case, the printing cost of the image data D increases.

Then, the image formation control unit 16 a performs 100% UCR processing by the under color removing unit 104 to replace the second color with black (step S123 ).

In this way, since the second color is converted to black, even if the color of the characters is a color other than black, such as gray or dark blue belonging to the chromatic system, the characters are printed with black toner, so printing costs can be suppressed. .

Next, the image forming control unit 16 a executes the full-color pattern mode, and the image forming unit 40 prints a character (C) using black toner and prints a specific pattern using color toner (step S124 ). In step S124 , the image forming unit 40 expresses the pattern color set in step S122 with color toner.

For example, the image forming unit 40 expresses colors such as dark green and red by mixing cyan, magenta, and yellow in a predetermined ratio.

The image forming apparatus 1 a updates the billing information of the user after executing the process of step S124 (step S125 ). For example, the image forming apparatus 1a prepares in advance to record in the management unit 17a the amount charged to the user according to the user's identification information (the amount is used as the charging information), and after image formation is performed in the full-color pattern mode, the The amount of money corresponding to the executed mode is sequentially recorded in the management unit 17a as billing information corresponding to the user identification information.

In this way, since the amount corresponding to the full-color pattern mode is sequentially recorded as charging information, it is easy to know how much the user is charged.

In addition, like the image forming apparatus 1 , the image forming apparatus 1 a may use each color group instead of each color, and use the number of appearances of each color group instead of the number of appearances of each color. At this time, as described above, let the color of the first color group G(1) be the first color, the color of the second color group G(2) be the second color, and the color of the third color group G(3) be the second color. Three colors, the Nth color is also obtained below (N is any integer).

In addition, the color setting unit 100 selects all colors whose appearance times are less than the second color in step S122 , for example, selects the third to sixth colors. Then, the color setting unit 100 may select, for example, each of the colors having the highest number of appearances from a plurality of colors included in the third to sixth colors (a plurality of colors whose density values are represented by 8 bits including the lower order bit). (that is, choose the third color, that is, the color that occurs most frequently in the third color group, the fourth color, that is, the color that occurs most frequently in the fourth color group, the fifth color, that is, the color that occurs most frequently in the fifth color group the color with the most number, and the sixth color (that is, the color with the most occurrences in the sixth color group), and set the four selected colors as pattern colors.

In addition, the process of setting the color with the largest number of appearances as the pattern color among the colors included in the third color to the Nth color can be the same as that of the colors included in the third color shown in FIG. 14 . The same process applies when setting the color with the most occurrences as the pattern color.

In addition, the image forming apparatus 1a may not have the management unit 17a, the operation input unit 18, the first setting unit 101, the second setting unit 102, the third setting unit 103, the fourth setting unit 105, the fifth setting unit The fixing unit 106 , the undercolor removing unit 104 and the image processing unit 120 do not perform steps S1 , S103 , S114 to S117 , S123 to S125 , S104 and S105 , but perform the following processes.

The image forming apparatus 1a may also perform steps S2, S4 to S8, and S10 to S12 in sequence, and if "Yes" in step S12, proceed to steps S118 and S122 to set the multiple colors whose occurrence times are less than the second color. Set as pattern color. As a result, when an image including a pattern whose color belongs to a chromatic system is printed, the color reproducibility of the pattern can be improved. Furthermore, step S123 may also be performed. Alternatively, step S124 can also be performed. Also, if NO in step S12, either the processing may be ended, or image formation may be performed in full-color mode, black-and-white mode, or monochrome mode, or the like.

In addition, steps S2, S4 to S8, S10 to S12, and S114 can also be performed in sequence, and if "No" in step S114, then steps S118 and S122 are performed to set the multiple colors whose occurrence times are less than the second color. Set as pattern color. In addition, when YES in step S114, the process may proceed to step S117 without performing steps S115 and S116, or the processing may be terminated.

In addition, a configuration in which steps S2, S4 to S8, S10 to S12, S114 to S118, and S122 are performed may also be employed.

In summary, the present invention provides an image forming apparatus including: an image data acquisition unit that acquires image data representing a color image; and a frequency distribution acquisition unit that, based on the image data acquired by the image data acquisition unit, obtains The colors of the pixels are assigned to each group to obtain a frequency distribution representing the number of appearances of each color; and the color setting section sets the first color with the largest number of appearances based on the frequency distribution obtained by the frequency distribution obtaining section to For the background color of the color image, set the second color that appears second only to the first color as the color of the text in the color image, and set the color that appears less than the second color is the pattern color in the color image, and the pattern color is the color of a specific pattern in the color image.

The specific patterns are, for example, non-character images such as logos, underlines, and colored parts. Usually, a document manuscript is formed by writing characters on a white sheet. In addition, patterns such as colored marks and underlines are often described in such document manuscripts. In this way, for an image mostly composed of characters and partly colored, that is, an image whose number of pixels of the design is smaller than a predetermined size determination value, the white color of the sheet becomes the background of the image. Therefore, the image data of such a document original contains colors in which white appears most frequently. In addition, the number of appearances of the color of the characters is second only to that of white.

Therefore, with the above structure, the first color with the largest number of appearances is set as the background color of the color image, the second color with the number of appearances next to the first color is set as the color of the text in the color image, and The color whose appearance frequency is less than the second color is set as the color of the specific pattern in the color image, that is, the pattern color, so when printing an image including the color pattern, the color reproducibility of the pattern can be improved.

In addition, in the above configuration, it is preferable that when the determination condition including the predetermined condition is satisfied, the color setting unit sets the third color that appears second only to the second color as the color of the pattern, The prescribed condition means that the difference between the sum of the number of occurrences of the prescribed object colors including the first color, the second color and the third color and the number of all pixels of the color image is less than a predetermined Pattern judgment value.

If the difference between the number of occurrences of the first color, the sum of the number of appearances of the second color and the number of appearances of the third color, and the total number of pixels of the color image is a large value above the first reference number, the first color, the second color Colors other than the secondary color and the tertiary color, such as the fourth color or the fifth color may appear more frequently. At this time, there is a high possibility that the pattern includes a plurality of colors.

And if the difference between the number of occurrences of the first color, the sum of the number of occurrences of the second color and the number of appearances of the third color, and the total number of pixels of the color image is a small value smaller than the first reference number, it can be speculated that it is a color image. The image hardly contains colors other than the first color, the second color, and the third color. In this case, there is a high possibility that the pattern is composed of the third color.

Then, with the above configuration, when the difference between the sum of the number of appearances of the predetermined target colors including the first color, the second color, and the third color and the total number of pixels of the color image is smaller than the pattern judgment value, the third The color is set to the pattern color. As a result, when the possibility that a specific pattern is composed of a third color (ie, a single color) is high, the third color is set as the pattern color.

Therefore, for example, when a monochrome image includes a pattern composed of a color belonging to a chromatic system, the color belonging to the chromatic system is set as the color of the pattern, and the pattern is printed using toner of the pattern color. As a result, when an image including a pattern composed of a color belonging to a chromatic system is printed, the color reproducibility of the pattern can be improved.

In addition, it is more desirable in the structure that: the object color includes the first color, the second color, the third color, and a fourth color whose occurrence frequency is second only to the third color; Said judging condition also includes other prescribed conditions, and said other prescribed condition means that the number of occurrences of said fourth color is less than the predetermined additional pattern judging value; when all prescribed conditions included in said judging condition are met, said color setting The setting part sets the third color as the design color.

If the difference between the number of appearances of the first color, the number of appearances of the second color, the sum of the number of appearances of the third color and the number of appearances of the fourth color and the total number of pixels of the color image is less than the second reference number, the first Colors other than the fourth color, for example, the fifth color and the sixth color have a low number of appearances, and the color of the pattern may be any one of the third color and the fourth color.

Moreover, if the number of occurrences of the fourth color is less than the judgment value of the additional pattern, it is more likely that the pattern is composed of the third color (that is, composed of a single color).

Therefore, with the above structure, when the predetermined condition is satisfied and the fourth color appears less than the additional pattern judgment value, the third color is set as the pattern color, so the time of setting the pattern color of a pattern composed of a single color can be improved. setting accuracy.

In addition, it is more ideal in the said structure that: said judging condition also includes other prescribed conditions, and said other prescribed condition means that the number of appearances of said third color is less than the pre-specified auxiliary size judging value; when said judging condition is satisfied When all the predetermined conditions are included, the color setting unit sets the third color as the pattern color.

If the number of occurrences of the third color is a large value equal to or greater than the auxiliary size determination value, there is a high possibility that the image area of the pattern composed of the third color presumed to be the pattern color is large. On the other hand, if the number of occurrences of the third color is a small value smaller than the auxiliary size determination value, there is a high possibility that the image area of the pattern composed of the third color presumed to be the pattern color is small.

With the above configuration, the color setting unit sets the third color as the pattern color when the number of appearances of the third color is smaller than the predetermined auxiliary size judgment value, and therefore only when the possibility of the image area of the pattern is small is high. The third color is set as the pattern color, and the pattern is printed using the color toner of the third color.

As a result, the color reproducibility of the design can be improved while suppressing the printing cost without consuming too much expensive color toner for printing the design.

In addition, by adopting a structure that can appropriately change the auxiliary size judgment value, it is possible to flexibly set the size of the image area of a specific pattern according to the user's request or the situation of the service provider. Provide monochrome pattern mode.

In addition, in the above configuration, it is preferable that the image data acquisition unit expresses the color of each pixel using each density value of predetermined three element colors; Assigning to each coordinate of the three-dimensional coordinates so that the respective colors are arranged on the three-dimensional coordinates as the respective groups, and by associating the respective colors with the number of occurrences, generating a representation on the three-dimensional coordinates The three-dimensional frequency distribution information of the frequency distribution; the color setting part selects the third color from colors other than the specified color, and the specified color is connected by a straight line on the three-dimensional coordinates of the three-dimensional frequency distribution information. The color arranged in the path formed by the first color and the second color is a color whose distance to the first color on the three-dimensional coordinates is greater than a predetermined judgment distance and to the second color. The color whose distance is greater than the judged distance is the color.

Since it can be presumed that the first color is the background color and the second color is the color of the text, the colors arranged in the path formed by connecting the first color and the second color with a straight line on the three-dimensional coordinates are due to the color of the text. There is a high possibility that the color is caused by bleeding, or the color of the character is lightened. Then, the third color is selected from colors other than this color, thereby further improving the reproducibility of the third color, that is, the pattern color.

In addition, in the above configuration, it is preferable that the image data acquisition unit expresses the color of each pixel by using each density value of predetermined three element colors, and expresses each density by a predetermined number of basic digits. value; the frequency distribution acquisition unit assigns each of the pre-specified upper-order positions in the concentration values of each element color to each coordinate of the three-dimensional coordinates, and sets the color groups sharing the upper-order positions as a group, and each group Arranged on the three-dimensional coordinates, and by associating each color group with the number of occurrences of each color group, three-dimensional frequency distribution information representing the frequency distribution of each color group is acquired; the color setting unit uses the Instead of the respective colors, a color group is selected as the third color from the color groups other than the color groups arranged in a predetermined area where the first color is connected with a straight line. The area formed by removing the first area and the second area from the area formed by the area and the second area, wherein the first area is on the three-dimensional coordinates and the distance from the color group as the first color is less than In an area of a predetermined Euclidean distance, the second area is an area whose distance to the color group serving as the second color on the three-dimensional coordinates is smaller than the predetermined Euclidean distance.

According to the above configuration, each color is replaced by each color group, thereby reducing the amount of data when acquiring the frequency distribution or when processing by the color setting unit. In addition, from the area formed by connecting the first area and the second area with a straight line, the color group arranged in the area obtained by removing the first area and the second area is a color caused by the color bleeding of the characters, or There is a high possibility that the density of the color of the characters will be a color produced by lightening. Therefore, by selecting a color group as the third color from color groups other than these color groups, it is possible to simplify the operation of the frequency distribution acquisition unit, unlike when all the basic bits are used to obtain the frequency distribution representing the number of occurrences of each color. The hardware structure can set the third color more precisely.

In addition, the above structure preferably further includes: an identification information input unit that accepts input of user identification information; a management unit that stores in advance the identification information of users who can only execute the black and white mode, and the black and white mode requires only one color to form the pattern of the image based on the image data; the setting unit accepts the setting of whether to allow the execution of the monochrome pattern mode for the user who has the identification information stored in the management unit and can only execute the black and white mode , the monochrome pattern mode is to use the toner of the second color set by the color setting part to print the characters in the color image, and use the toner of the second color set by the color setting part a mode in which the specific pattern is printed with the toner of the third color; When identification information of a user capable of executing the monochrome pattern is input, and the setting unit accepts a setting to allow the user with the identification information to execute the monochrome pattern mode, the control unit allows the A user of the monochrome mode executes the monochrome mode and the monochrome pattern mode.

In general, when image data printing service is provided, the amount charged to the user may be different in the black and white mode (black and white copy) and the full color mode (color copy). At this time, often, the charging amount in the black-and-white mode is lower than that in the full-color mode.

However, for example, when business documents of an enterprise are dominated by black and white images, and only a small portion of specific images such as logos, underlines, and colored parts exist, users want to print black and white images in black and white, and print specific images in color .

Also, when the image area of a specific pattern such as logos, underlines, and colored parts is small, the cost of the monochrome pattern mode is only slightly higher than that of the black and white mode because the amount of color toner consumed in the monochrome pattern mode is very small That's all. Therefore, even if the charging amount in the monochrome pattern mode is set to be substantially the same as that in the monochrome mode, or slightly higher than that in the monochrome mode, the service provider will not incur a loss.

With the above structure, when a user who can execute only the monochrome mode has made a setting to allow execution of the monochrome pattern mode, the monochrome pattern mode can be executed.

As a result, when the setting to allow the execution of the monochrome pattern mode has been made, and the image area of the specific image is small, it is possible to easily and inexpensively provide monochrome patterns for printing a specific pattern in pattern colors to users who can only execute the black and white mode. model.

Furthermore, it is preferable that the above configuration further includes an image processing unit that performs background color changing processing of changing the background color of the color image to a predetermined color with respect to the image data.

With the said structure, even if the background color concentration of the original of the color image is relatively deep, or the color of the back of the original is shown through the front, thereby causing the pixels in the color image that should be the background color to become pixels of other colors, the original background color will be used. Colored pixel color to replace the background color.

As a result, the background color, character color, and pattern color of a color image can be faithfully reproduced.

In addition, in the above configuration, it is preferable that the color setting unit sets a plurality of colors that appear less frequently than the second color in the frequency distribution as the pattern color, and, based on the appearance The number of appearances of any color whose frequency is less than the second color, the number of appearances of the first color, and the number of appearances of the second color determines whether to set the full-color pattern mode, and the full-color pattern mode is A mode of printing the specific pattern using the pattern color; the image forming apparatus further includes a control unit that uses the second The text in the color image is printed with toner of the color, and the specific pattern is printed with the toner of the color of the pattern.

Panchromatic means multiple colors.

With the above structure, it is judged that the color image part contains a plurality of colors belonging to There is a specific pattern composed of colors in the color system, and the full-color pattern mode is set, and multiple colors that appear less frequently than the color of the text are set as the pattern color.

Next, the full-color pattern mode is executed, characters are printed with the toner of the second color, and a specific pattern is printed with the toner of the pattern color set by the color setting unit.

Accordingly, when an image of a specific pattern composed of a plurality of colors belonging to a chromatic system is included in the printed portion, the color reproducibility of the specific pattern can be improved.

In addition, it is more ideal in the structure that: when the difference between the sum of the number of appearances of the first color and the number of appearances of the second color and the total number of pixels of the color image is smaller than the predetermined size judgment value, and when the number of occurrences of the fourth color reaches a predetermined number of color judgment values or more, the color setting part sets the full-color pattern mode, wherein the fourth color is second only to the third color. The color of the color, the tertiary color is the color with the second most occurrences after the second color.

If the difference between the sum of the number of appearances of the first color that is estimated to be the background color and the number of appearances of the second color that is estimated to be the color of the text and the total number of pixels of the color image is less than the size judgment value, it can be determined that The area of the specific pattern formed by colors other than the first color and the second color, that is, colors presumed to be pattern colors, is small.

Also, if the number of occurrences of the fourth color is a large value equal to or greater than a plurality of color judgment values, it is highly likely that the design color includes a plurality of colors.

Therefore, with the above configuration, only when the image contains a specific pattern with a small area and composed of two or more colors belonging to the chromatic system, the full-color pattern mode is set and the specific pattern is printed with each color toner. As a result, high-priced color toners are not consumed to print a specific pattern, and printing costs can be suppressed while the color reproducibility of the pattern can be improved.

In addition, it is more ideal in the structure that: when the difference between the sum of the number of appearances of the first color and the number of appearances of the second color and the total number of pixels of the color image is smaller than the predetermined size judgment value, and the number of appearances of the fourth color is less than a plurality of predetermined color judgment values, and the number of appearances of the first color, the number of appearances of the second color, the number of appearances of the third color and the number of appearances of the fourth color When the difference between the sum of the number of occurrences and the total number of pixels of the color image is greater than or equal to a predetermined number of additional color judgment values, the color setting section sets the full-color pattern mode, wherein the second The third color is a color whose appearance frequency is second only to the second color, and the fourth color is a color whose appearance frequency is second only to the third color.

When the difference between the sum of the number of appearances of the first color and the number of appearances of the second color and the total number of pixels of the color image is smaller than the size judgment value, it can be judged that the area of the specific pattern is small. And, if the number of appearances of the fourth color is less than a plurality of color judgment values, it is more likely that the color of the specific pattern is the third color (ie monochrome). However, even if the number of appearances of the fourth color is less than a plurality of color judgment values, if the sum of the number of appearances of the first color, the number of appearances of the second color, the number of appearances of the third color, and the number of appearances of the fourth color is equal to the color image If the difference between the total number of pixels is more than a plurality of color judgment values, there is a high possibility that the specific pattern is composed of many colors with a very small number of occurrences.

Thus, with the structure, even if the number of appearances of the fourth color is smaller than a plurality of color judgment values, if the number of appearances of the first color, the number of appearances of the second color, the number of appearances of the third color, and the number of appearances of the fourth color And, if the difference from the total number of pixels of the color image is more than a plurality of color judgment values, the color setting unit judges that the specific pattern is composed of a plurality of colors, and sets the full-color pattern mode. As a result, the accuracy of determination in determining whether a specific pattern is composed of a single color or a plurality of colors can be improved.

In addition, in the above structure, it is more desirable that the ratio of the sum of the number of appearances of the first color and the number of appearances of the second color to the total number of pixels of the color image is above a predetermined reference ratio, And when the number of occurrences of the fourth color is more than a plurality of predetermined color judgment values, the color setting part sets the full-color pattern mode, wherein the fourth color is the second only to the third color. color, the tertiary color is the color that occurs second only to the second color.

When the ratio of the sum of the number of appearances of the first color and the number of appearances of the second color to the total number of pixels of the color image is a small ratio smaller than the reference ratio, the color of the specific pattern whose number of appearances is less than that of the second color is displayed in the entire image There is a high probability that the proportion in the If the proportion of the area occupied by a specific pattern in the entire image is large, even if the size of the recording paper set to print the specific pattern is larger, the printing fee paid by the user will increase, because the consumption cost of color toner accounts for the cost The proportion is very large, which may lead to losses for the service provider. Furthermore, if the number of occurrences of the fourth color is greater than or equal to a plurality of color determination values, it is highly likely that the design color includes a plurality of colors.

Therefore, with the above structure, when the ratio of the sum of the number of appearances of the first color and the number of appearances of the second color in the total number of pixels of the color image exceeds the reference ratio, that is, the percentage of the specific pattern in the entire image When the ratio is small and the number of appearances of the fourth color is greater than the predetermined second reference number, the full-color pattern mode is set.

Thus, when an image contains a specific pattern composed of two or more colors belonging to the chromatic system, the full-color pattern mode will not be set when the specific image accounts for more than a predetermined proportion of the entire image, so the user can pay for it. The proportion of the consumption cost of color toner in the cost is kept within a small range.

Therefore, if the service provider sets the size of the recording paper used for printing a specific pattern to be larger, the printing fee paid by the user is increased, and the service provider can provide the user with the advantage of not incurring a loss. Color toner to print specific pattern service.

In addition, in the above configuration, it is preferable that the image data acquisition unit expresses the color of each pixel using each density value of predetermined three element colors; Assigning to each coordinate of the three-dimensional coordinates so that the respective colors are arranged on the three-dimensional coordinates as the respective groups, and by associating the respective colors with the number of occurrences, generating a representation on the three-dimensional coordinates The three-dimensional frequency distribution information of the frequency distribution; the color setting part sets the color of the pattern according to the order of the appearance times of the remaining colors other than the specified color, and the specified color is in the three-dimensional frequency distribution information. The color arranged in the path formed by connecting the first color and the second color with a straight line on the three-dimensional coordinates, and the distance from the first color on the three-dimensional coordinates to the first color is greater than the predetermined judgment distance, And the color whose distance to the second color is greater than the judgment distance.

Since it can be presumed that the first color is the background color and the second color is the color of the text, the colors arranged in the path formed by connecting the first color and the second color with a straight line on the three-dimensional coordinates are due to the color of the text. There is a high possibility that the color is caused by bleeding, or the color of the character is lightened. Then, by selecting the pattern color from colors other than this color, the color reproducibility of the pattern can be improved.

In addition, in the above configuration, it is preferable that the image data acquisition unit expresses the color of each pixel by using each density value of predetermined three element colors, and expresses each density by a predetermined number of basic digits. value; the frequency distribution acquisition unit assigns each of the pre-specified upper-order positions in the concentration values of each element color to each coordinate of the three-dimensional coordinates, and sets the color groups sharing the upper-order positions as a group, and each group Arranged on the three-dimensional coordinates, and by associating each color group with the number of occurrences of each color group, three-dimensional frequency distribution information representing the frequency distribution of each color group is acquired; the color setting unit uses the Each of the above color groups is used instead of each of the colors, and the pattern colors are set according to the order of the appearance times of the remaining color groups outside the color group arranged in the predetermined area. In the area formed by the first area and the second area, the area obtained by removing the first area and the second area, wherein the first area is the distance from the color group as the first color on the three-dimensional coordinates An area smaller than a predetermined Euclidean distance, the second area is an area whose distance to a color group serving as the second color of the pattern on the three-dimensional coordinates is smaller than a predetermined Euclidean distance.

According to the above configuration, each color is replaced by each color group, thereby reducing the amount of data when acquiring the frequency distribution or when processing by the color setting unit. In addition, from the area formed by connecting the first area and the second area with a straight line, the color group in the area obtained by removing the first area and the second area is the color caused by the color bleeding of the characters, or the color of the characters. There is a high possibility of a color produced by lightening the density of the color. Therefore, the design color is selected from a color group other than these color groups, which is different from the case of obtaining the frequency distribution representing the number of appearances of each color by using all the basic bits, and it is possible to simplify the hardware structure of the frequency distribution acquisition part and to achieve Set the pattern color more precisely.

In addition, in the above structure, it is preferable that the color of each pixel is represented by a density value of cyan, a density value of magenta, and a density value of yellow, or by a density value of red, a density value of green, and a density value of blue. The image forming apparatus further includes: an image forming section that uses the cyan toner, the magenta toner, the yellow toner, and the black toner to form performing image formation, or performing image formation using the red toner, the green toner, the blue toner, and black toner; Parts corresponding to gray in each density value of each pixel are replaced with black, wherein, when the color setting part sets the full-color pattern mode, the background color removal part replaces the second color with 100% undertone removal treatment of the black.

In order to improve the color reproducibility of specific patterns such as logos, underlines, colored parts, etc., it may be considered to print documents including the specific pattern in full-color mode. However, in the full-color mode, black toner is not used for characters, and color toners that are more expensive than black toner are often mixed to synthesize black for printing. In this case, the cost required to print the text increases compared to the case of printing the text using black toner.

However, with the above configuration, the undercolor remover usually performs so-called UCR processing by replacing the portion corresponding to gray in each density value of each pixel of cyan, magenta, and yellow, or red, green, and blue with black. .

Furthermore, when the color setting unit sets the full-color pattern mode, the undercolor removing unit replaces the second color estimated to be the color of the characters with black at a rate of 100%. That is, when the full-color pattern mode is set, the second color is replaced with black, so when the full-color pattern mode is executed, characters are printed with black toner.

As a result, printing costs can be suppressed compared to the case where a plurality of expensive color toners are mixed to generate the color of characters, and the charge amount in the full-color pattern mode can be easily suppressed.

In addition, the above structure preferably further includes: an identification information input unit that accepts input of user identification information; a management unit that stores in advance identification information indicating users limited to monochrome mode, and the users limited to monochrome mode are only A user who can execute the black and white mode; and a first setting section accepting whether to allow the user limited to the black and white mode to execute the setting of the full-color pattern mode, wherein when the first setting section accepts the permission of the limited When a user in monochrome mode sets the full-color pattern mode and the identification information input unit accepts an input of identification information indicating that the user in monochrome mode is limited, the control unit allows the user in monochrome mode to The black-and-white mode and the full-color pattern mode are implemented.

In general, when image data printing service is provided, the amount charged to the user may be different in the black and white mode (black and white copy) and the full color mode (color copy). At this time, the price of color toner used in full-color mode is higher than that of black toner used in black-and-white mode, so the amount charged to users in full-color mode is often higher than that charged in black-and-white mode amount.

However, for example, when business documents of an enterprise are dominated by black and white images, and only a small portion of specific images such as logos, underlines, and colored parts exist, users want to print black and white images in black and white, and print specific images in color .

Also, when the image area of a specific pattern such as logos, underlines, and colored parts is small, the full-color pattern mode requires only a little more cost than the black-and-white mode because the amount of color toner consumed in the full-color pattern mode is very small. only high. Therefore, even if the charging amount in the full-color pattern mode is set to be substantially the same as that in the black-and-white mode, or slightly higher than that in the black-and-white mode, the service provider will not incur a loss.

With the above structure, when the user who can execute only the black-and-white mode has made a setting to allow the execution of the full-color pattern mode, the full-color pattern mode can be executed. As a result, when a setting is made to allow the full-color pattern mode, and the image area of the specific image is small, it is possible to easily and inexpensively provide a full-color pattern that prints a specific pattern in the pattern color to a user who can only execute the black-and-white mode. model.

In addition, it is preferable that the above structure further includes a second setting unit for setting at least the size judgment value.

With the above structure, the service provider can flexibly set the full-color pattern mode for a specific image according to its own situation or user's requirements.

In addition, it is preferable that the above structure further includes a third setting unit for setting at least the reference ratio.

By adopting the structure, the service provider can flexibly set the proportion of the specific image in the whole image according to its own situation or user's requirements, and set the full-color pattern mode.

Furthermore, it is preferable that the above configuration further includes an image processing unit that performs background color changing processing of changing the background color to a predetermined color with respect to the image data.

With this configuration, the background color of a color image can be changed to a predetermined color. Thus, even if the background color density of the original of the color image is relatively deep, or the color of the back side of the original is reflected on the front side, so that when the pixels that should be the background color in the color image become pixels of other colors, the pixels of the original background color will be used. Pixel color to replace the background color. As a result, the background color, character color, and pattern color of a color image can be faithfully reproduced.

In addition, in the above configuration, it is preferable that the image data acquisition unit expresses the color of each pixel using each density value of predetermined three element colors, and expresses the density value with a predetermined number of basic digits. The frequency distribution acquisition unit acquires the frequency distribution by using a color group as the group, the color groups respectively including colors sharing a predetermined upper-order position in the basic number of digits; the color setting unit Use the color groups to replace the colors, and according to the number of occurrences of the first color group with the largest number of occurrences in the frequency distribution, the number of occurrences of the second color group with the second highest number of occurrences, and the number of occurrences less than The number of occurrences of any color group in the plurality of color groups of the second color group determines whether to set the full-color pattern mode, and when the full-color pattern mode is set, the number of occurrences is less than the Select the colors that appear most often in each color group of the second color group, and set the selected colors as the design colors.

With this configuration, unlike when the frequency distribution representing the number of appearances of each color is obtained using all the basic bits, the frequency distribution acquisition unit obtains a frequency distribution representing the number of appearances of each color group sharing the upper-order bits (that is, a part of the basic bits). frequency distribution. Furthermore, the color setting unit acquires the color group to which the first color belongs, the color group to which the second color belongs, and the color group to which the color estimated to be the design color belongs, respectively, using the frequency distribution of the color group, and based on the acquired color Group to set the full-color pattern mode.

As a result, it is possible to simplify the hardware configuration of the frequency distribution acquisition unit and set the full-color pattern mode compared to the case of acquiring the frequency distribution indicating the number of appearances of each color using all the basic bits.

Claims (19)

1. an image processing system, is characterized in that comprising:

Image data acquisition portion, obtains the view data that represents coloured image;

Frequency distributed acquisition portion, according to the view data of being obtained by described image data acquisition portion, gives each group by the color assignment of each pixel of this view data, to obtain the frequency of the occurrence number that represents each color, distributes; And

Color settings portion, according to the frequency of being obtained by described frequency distributed acquisition portion, distribute, the background colour that is described coloured image by the first maximum color settings of occurrence number, the second color settings that occurrence number is only second to described the first color is the color of the word in described coloured image

Wherein, when meeting the Rule of judgment that comprises rated condition, described color settings portion is only second to using occurrence number the style color that the 3rd color settings of described the second color is the color of the specific style in described coloured image, described rated condition refers to, the difference between the occurrence number sum of the object color of the regulation that comprises described the first color, the second color and described the 3rd color and the full figure prime number of described coloured image is less than the style judgment value of predetermining.

2. image processing system according to claim 1, is characterized in that:

Described object color comprises the 4th color that described the first color, described the second color, described the 3rd color and occurrence number are only second to described the 3rd color,

Described Rule of judgment also comprises miscellaneous stipulations condition, this miscellaneous stipulations condition refer to the occurrence number of described the 4th color be less than predetermine append style judgment value,

When meeting all rated conditions that described Rule of judgment comprises, described color settings portion is described style color by described the 3rd color settings.

3. image processing system according to claim 1, is characterized in that:

Described Rule of judgment also comprises miscellaneous stipulations condition, and this miscellaneous stipulations condition refers to that the occurrence number of described the 3rd color is less than the auxiliary big or small judgment value of predetermining,

When meeting all rated conditions that described Rule of judgment comprises, described color settings portion is described style color by described the 3rd color settings.

4. image processing system according to claim 1, is characterized in that:

Described image data acquisition portion utilizes each concentration value of three key element colors predetermining to represent the color of described each pixel,

Described frequency distributed acquisition portion distributes to described each concentration value on each coordinate of three-dimensional coordinate, using described each color is configured on three-dimensional coordinate as described each group, and, by this each color is associated with described occurrence number respectively, be created on the three-dimensional frequency distributed intelligence that represents described frequency distribution on three-dimensional coordinate

Selected described the 3rd color the color of described color settings portion outside specified color, this specified color, being on the three-dimensional coordinate of described three-dimensional frequency distributed intelligence, with straight line, to connect described the first color and described the second color and the color that configures in the path that forms, is again that the distance to described the first color is greater than the judging distance of predetermining and the color that is greater than described judging distance to the distance of described the second color on described three-dimensional coordinate.

5. image processing system according to claim 1, is characterized in that:

Described image data acquisition portion utilizes each concentration value of three key element colors predetermining to represent the color of described each pixel, and represents this each concentration value with the basic figure place of predetermining,

Described frequency distributed acquisition portion by the concentration value of each key element color, predetermine each on tagmeme distribute on each coordinate of three-dimensional coordinate, and the color group who shares tagmeme on this is made as to a group, each group is configured on described three-dimensional coordinate, and, by each color group and this each color group's occurrence number is associated, obtain the three-dimensional frequency distributed intelligence of the frequency distribution that represents described each color group

Described each color group of described color settings portion's utilization replaces described each color, and the selected color group as described the 3rd color the color group outside being configured in the color group in regulation region, described regulation region, the region forming from connecting first area and second area with straight line, to remove the region that this first area and second area obtain, wherein said first area is on described three-dimensional coordinate, to the distance of the color group as described the first color, to be less than the region of the Euclidean distance of predetermining, described second area is on described three-dimensional coordinate, to the distance of the color group as described the second color, to be less than the region of the Euclidean distance of predetermining.

6. image processing system according to claim 1, characterized by further comprising:

Identifying information input part, the input of the identifying information of accepted user;

Management department, the pre-stored identifying information that has the user that can only carry out white-black pattern, this white-black pattern is the pattern of the image based on described view data that only forms by a color;

Configuration part, for having, be stored in user in described management department, that can only carry out the identifying information of white-black pattern, accept the setting that whether allows to carry out monochromatic style pattern, this monochrome style pattern, be to utilize the toner of described the second color of being set by described color settings portion to print the word in described coloured image, and utilize the toner of described the 3rd color of being set by described color settings portion to print the pattern of described specific style; And

Control part, carries out image with described white-black pattern and described monochromatic style pattern and forms, wherein,

When described identifying information input part is accepted the input of the user's that can only carry out described white-black pattern identifying information, and described configuration part is when accepting the user who allows to have this identifying information and carrying out the setting of described monochromatic style pattern, the user that can only carry out described white-black pattern described in described control part allows carries out described white-black pattern and described monochromatic style pattern.

7. image processing system according to claim 1, characterized by further comprising image processing part, and this image processing part carries out the background colour of described coloured image to change into for described view data the background colour change processing of the color of predetermining.

8. an image processing system, is characterized in that comprising:

Image data acquisition portion, obtains the view data that represents coloured image;

Frequency distributed acquisition portion, according to the view data of being obtained by described image data acquisition portion, gives each group by the color assignment of each pixel of this view data, to obtain the frequency of the occurrence number that represents each color, distributes; And

Color settings portion, according to the frequency of being obtained by described frequency distributed acquisition portion, distribute, the background colour that is described coloured image by the first maximum color settings of occurrence number, the second color settings that occurrence number is only second to described the first color is the color of the word in described coloured image

Wherein, described color settings portion occurrence number in described frequency distributes is less than the style color that a plurality of color settings of described the second color are the color of the specific style in described coloured image, and, the occurrence number that is less than the occurrence number of arbitrary color of described the second color, the occurrence number of described the first color and described the second color according to described occurrence number, determine whether to set panchromatic style pattern, this panchromatic style pattern is to utilize described style color to print the pattern of described specific style

Described image processing system also comprises control part, when the described panchromatic style pattern of described color settings portion's setting, described control part utilizes the toner of described the second color to print the word in described coloured image, and utilizes the toner of described style color to print described specific style.

9. image processing system according to claim 8, it is characterized in that: when the occurrence number of described the first color and the occurrence number sum of described the second color are less than with the difference between the full figure prime number of described coloured image the big or small judgment value of predetermining, and the occurrence number of the 4th color reaches a plurality of color judgment value of predetermining when above, the described panchromatic style pattern of described color settings portion's setting, wherein said the 4th color is the color that occurrence number is only second to the 3rd color, and the 3rd color is the color that occurrence number is only second to the second color.

10. image processing system according to claim 8, it is characterized in that: when the occurrence number of described the first color and the occurrence number sum of described the second color are less than with the difference between the full figure prime number of described coloured image the big or small judgment value of predetermining, and the occurrence number of the 4th color is less than a plurality of color judgment value of predetermining, and the occurrence number of described the first color, the occurrence number of described the second color, the occurrence number sum of the occurrence number of the 3rd color and described the 4th color with the difference between the full figure prime number of described coloured image reach predetermine append a plurality of color judgment value when above, the described panchromatic style pattern of described color settings portion's setting, wherein said the 3rd color is the color that occurrence number is only second to the second color, described the 4th color is the color that occurrence number is only second to the 3rd color.

11. image processing systems according to claim 8, it is characterized in that: the occurrence number sum of the occurrence number of described the first color and described the second color with respect to the ratio of the full figure prime number of described coloured image more than the benchmark ratio of predetermining, and the occurrence number of the 4th color is when a plurality of color judgment value of predetermining are above, the described panchromatic style pattern of described color settings portion's setting, wherein said the 4th color is the color that occurrence number is only second to the 3rd color, and the 3rd color is the color that occurrence number is only second to the second color.

12. image processing systems according to claim 8, is characterized in that:

Described image data acquisition portion utilizes each concentration value of three key element colors predetermining to represent the color of described each pixel,

Described frequency distributed acquisition portion distributes to described each concentration value on each coordinate of three-dimensional coordinate, using described each color is configured on three-dimensional coordinate as described each group, and, by this each color is associated with described occurrence number respectively, be created on the three-dimensional frequency distributed intelligence that represents described frequency distribution on three-dimensional coordinate

The described color settings portion according to the rules order of the occurrence number of the remaining color outside color sets described style color, this specified color, being on the three-dimensional coordinate of described three-dimensional frequency distributed intelligence, with straight line, to connect described the first color and described the second color and the color that configures in the path that forms, is again that the distance to described the first color is greater than the judging distance of predetermining and the color that is greater than described judging distance to the distance of described the second color on described three-dimensional coordinate.

13. image processing systems according to claim 8, is characterized in that:

Described image data acquisition portion utilizes each concentration value of three key element colors predetermining to represent the color of described each pixel, and represents this each concentration value with the basic figure place of predetermining,

Described frequency distributed acquisition portion by the concentration value of each key element color, predetermine each on tagmeme distribute on each coordinate of three-dimensional coordinate, and the color group who shares tagmeme on this is made as to a group, each group is configured on described three-dimensional coordinate, and, by each color group and this each color group's occurrence number is associated, obtain the three-dimensional frequency distributed intelligence of the frequency distribution that represents described each color group

Described each color group of described color settings portion's utilization replaces described each color, according to the order that is configured in the occurrence number of the remaining color group outside the color group in regulation region, set described style color, described regulation region, the region forming from connecting first area and second area with straight line, to remove the region that this first area and second area obtain, wherein said first area is on described three-dimensional coordinate, to the distance of the color group as described the first color, to be less than the region of the Euclidean distance of predetermining, described second area is on described three-dimensional coordinate, to the distance of the color group as described style the second color, to be less than the region of the Euclidean distance of predetermining.

14. image processing systems according to claim 8, is characterized in that:

The color of described each pixel by the concentration value of cyan, the concentration value of magenta and yellow concentration value represent, or represented by red concentration value, green concentration value and blue concentration value,

Described image processing system also comprises:

Image forming part, utilize the toner of described cyan, the toner of the toner of described magenta, described yellow and the toner of black carry out image formation, or utilize the toner of the toner of described redness, the toner of described green and described blueness and the toner of black to carry out image formation; And

Undercolour removal portion, is replaced into black by the part corresponding to grey in described each concentration value of described each pixel, wherein,

When described color settings portion sets panchromatic style pattern, described undercolour removal portion carries out described the second color to be replaced into 100% undercolour removal of described black and processes.

15. image processing systems according to claim 8, characterized by further comprising:

Identifying information input part, the input of the identifying information of accepted user;

Management department, the pre-stored identifying information that has expression to be limited to the user of white-black pattern, this user who is limited to white-black pattern is the user that can only carry out white-black pattern; And

The first configuration part, accepts the setting that the user who is limited to white-black pattern described in whether allowing carries out described panchromatic style pattern, wherein,

When the setting that the user who is limited to white-black pattern described in permission carries out described panchromatic style pattern is accepted in described the first configuration part, and when described identifying information input part is accepted the user's who is limited to white-black pattern described in expression the input of identifying information, the user who is limited to white-black pattern described in described control part allows carries out described white-black pattern and described panchromatic style pattern.

16. image processing systems according to claim 9, characterized by further comprising the second configuration part, and this second configuration part is at least setting described big or small judgment value.

17. image processing systems according to claim 11, characterized by further comprising the 3rd configuration part, and the 3rd configuration part is at least setting described benchmark ratio.

18. image processing systems according to claim 8, characterized by further comprising image processing part, and this image processing part carries out described background colour to change into for described view data the background colour change processing of the color of predetermining.

19. image processing systems according to claim 8, is characterized in that:

Described image data acquisition portion utilizes each concentration value of three key element colors predetermining to represent the color of described each pixel, and represents this concentration value with the basic figure place of predetermining,

Described frequency distributed acquisition portion obtains described frequency using color group as described group and distributes, and described color group comprises respectively the color of sharing the upper tagmeme of predetermining in described basic figure place,

Described each color group of described color settings portion's utilization replaces described each color, and the first color group's that in distributing according to described frequency, occurrence number is maximum occurrence number, deputy the second color group's of occurrence number occurrence number and occurrence number are less than the occurrence number of arbitrary color group in a plurality of color groups of the second color group, determine whether setting described panchromatic style pattern, and, when setting described panchromatic style pattern, from being less than each color group of described the second color group, occurrence number selects respectively each color that occurrence number is maximum, and selected this each color is all set as to described style color.